What is Relationship Between International Law and Municipal Law

Key Takeaways

• International law and municipal law operate at different levels but frequently interact. International law primarily regulates relations among States and other international actors, while municipal law governs persons, institutions and authorities within a State.
• Monism treats international law and municipal law as parts of one legal system, whereas dualism treats them as separate legal systems having different sources, subjects and methods of operation.
• Under a dualist system, a treaty generally requires incorporation or transformation into domestic law before its provisions can directly create enforceable rights and obligations before national courts.
• India broadly follows a dualist approach to treaties. Entering into an international treaty can bind India internationally, but legislation may be required when treaty obligations affect existing Indian law or the rights of individuals.
• Article 51(c) of the Constitution directs the State to foster respect for international law and treaty obligations, while Article 253 empowers Parliament to make laws for implementing treaties, agreements, conventions and decisions made at international conferences.
• Indian courts may rely on international conventions to interpret domestic law where there is no inconsistency with existing law. The Supreme Court’s decision in Vishaka v State of Rajasthan is an important example.
• In the case of a direct and unavoidable conflict between an international rule and an Act of Parliament, municipal law ordinarily prevails before Indian courts. The Supreme Court explained this principle in Gramophone Company of India Ltd v Birendra Bahadur Pandey.

What Is International Law?

International law is the body of legal rules and principles governing relations within the international community. Traditionally, it was understood mainly as a system regulating relations between sovereign States. Modern international law has expanded considerably and also concerns international organisations and, in several areas, individuals and other entities.

International law covers matters such as treaties, diplomatic relations, human rights, international trade, armed conflict, environmental protection, maritime law, international criminal responsibility and relations between States.

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Its important sources of international law include international treaties, customary international law and general principles recognised within international legal systems.

Unlike municipal law, international law does not operate through a single worldwide legislature, executive or court comparable to the institutions existing within a sovereign State. Its creation, implementation and enforcement therefore differ considerably from domestic legal systems.

What Is Municipal Law?

Municipal law means the domestic or internal law of a State. The word “municipal” in this context does not mean municipal corporation law or local government law. It refers to the entire body of law operating within a particular country.

In India, municipal law includes the Constitution of India, laws enacted by Parliament and State Legislatures, delegated legislation, binding judicial precedents and other legally recognised rules.

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Municipal law governs relationships between individuals, between individuals and the State, and among governmental institutions. Criminal law, constitutional law, contract law, property law, administrative law and company law are examples of municipal law.

The central issue in studying the difference between Municipal Law and International Law is therefore not merely that two forms of law exist. The important question is how a rule created at the international level acquires legal effect within a domestic legal system.

What Is the Relationship Between International Law and Municipal Law?

International law and municipal law are closely connected because States perform many of their international obligations through domestic institutions.

A State may enter into an international treaty concerning human rights, environmental protection, taxation, trade, intellectual property or criminal cooperation. However, implementation of that obligation may require action by Parliament, administrative authorities or courts within the State.

The relationship becomes especially important when questions arise such as whether a treaty can be directly enforced in a national court, whether international law can override an Act of Parliament, or whether courts can rely upon international conventions while interpreting constitutional rights.

Two principal theories have historically been used to explain this relationship: Monism and Dualism.

What Is the Monistic Theory?

Meaning of Monism

The Monistic Theory views international law and municipal law as parts of a single legal system or unified legal order.

Under this approach, international law is not necessarily required to undergo a separate legal transformation merely because it originates outside the domestic legal system. International norms may operate within national law according to the constitutional structure of the particular State.

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The Supreme Court explained the theoretical distinction in Union of India v Agricas LLP, observing that monistic systems include international treaties within domestic law and treat international and national norms as belonging to the same normative system.

Main Features of Monism

Monism rejects the idea that international and municipal law are completely independent bodies of law.

It generally proceeds on the basis that international and domestic legal norms can operate within the same legal structure. Individuals may also be recognised as subjects of international law rather than international law being confined entirely to States.

Certain monist theories also give international law a superior position where international and domestic norms conflict. However, the exact constitutional position varies between countries. Monism therefore does not necessarily mean that every treaty automatically overrides every domestic rule.

Hans Kelsen is commonly associated with the monistic understanding of law because of his conception of legal rules as belonging to a unified normative order.

What Is the Dualistic Theory?

Meaning of Dualism

The Dualistic Theory considers international law and municipal law to be separate and independent legal systems.

International law operates at the international level, while municipal law operates within the State. A rule belonging to one legal system does not automatically become part of the other.

The Supreme Court in Union of India v Agricas LLP described dualism as the position that international and municipal law operate separately and that an international rule must generally be transformed through appropriate constitutional machinery before it obtains effect within domestic jurisdiction.

Why Does Dualism Treat the Two Systems Separately?

The dualist theory emphasises differences in the sources and subjects of the two systems.

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Municipal law derives authority from the constitutional institutions of the State. Parliament, State Legislatures, constitutional provisions and courts operate within a domestic constitutional structure.

International law, on the other hand, derives from sources such as treaties and customary international law and traditionally regulates legal relations between sovereign States.

Accordingly, merely entering into a treaty does not necessarily make every treaty provision directly enforceable by individuals before national courts.

Jurists such as Heinrich Triepel and Dionisio Anzilotti are closely associated with the dualist theory.

Difference Between Monism and Dualism

The distinction is useful for understanding legal theory, but modern constitutional systems do not always follow either model in an absolute form.

What Is the Transformation Theory?

The Transformation Theory is closely connected with dualism.

According to this theory, an international rule, particularly a treaty rule, must be transformed into municipal law before it can operate as domestic law.

Suppose a State enters into an international convention requiring a particular activity to be criminalised. The treaty obligation may bind the State internationally. However, if the domestic legal system requires legislative implementation, the conduct does not automatically become a criminal offence merely because the treaty has been ratified.

The legislature must enact the necessary law creating the offence, punishment and enforcement mechanism.

Transformation therefore explains the movement of an international obligation into the domestic legal order through constitutional law-making procedures.

What Is the Specific Adoption Theory?

The Specific Adoption Theory similarly emphasises that international rules require acceptance through domestic legal processes before they become enforceable as municipal law.

The theory is especially relevant where the constitutional authority responsible for entering into international agreements is different from the authority responsible for changing domestic law.

For example, the executive may represent a State in international relations and conclude agreements, while the legislature possesses constitutional authority to alter rights and liabilities within domestic law.

Specific adoption therefore protects the domestic constitutional distribution of legislative power.

What Is the Delegation Theory?

The Delegation Theory takes a somewhat different approach.

It considers international law as permitting States to determine the manner in which their international obligations will operate internally. International law creates the obligation, but the constitutional law of each State determines the mechanism through which that obligation will be implemented.

The theory therefore focuses less on the conversion of one legal system into another and more on the freedom given to national legal systems to select their own methods of implementation.

What Happens When International Law Conflicts With Municipal Law?

The answer depends significantly on the forum in which the dispute arises.

Position at the International Level

At the international level, the existence of a contrary domestic law does not ordinarily remove the State’s international responsibility.

A State cannot generally avoid an international obligation merely by stating that its domestic institutions or legislation prevented compliance. International obligations operate at the level of relations between States and other recognised international actors.

Domestic law and international law may therefore produce different legal consequences in relation to the same situation.

Position Before Domestic Courts

A national court functions under the Constitution and laws of its own country.

Consequently, the domestic court must determine whether the international rule has been incorporated, whether constitutional provisions allow its direct application and whether it conflicts with legislation already in force.

This distinction explains why a State may remain bound internationally even when a particular treaty provision cannot directly be invoked before its national courts.

What Is the Position in India?

India broadly follows a dualist approach in relation to treaties, but the Indian position cannot be described as complete separation between international and municipal law.

International treaties may bind India on the international plane, while their domestic enforceability depends upon the constitutional framework and the nature of the treaty obligation.

The Supreme Court in Maganbhai Ishwarbhai Patel v Union of India distinguished between the formation of treaty obligations and their domestic performance. It recognised that the Union executive is competent to represent India internationally and undertake obligations, but treaty obligations do not by their own force necessarily alter the rights of individuals under Indian law. Legislative action becomes necessary where implementation requires modification of Indian law or affects existing legal rights.

This distinction is fundamental to understanding India’s approach.

Which Constitutional Provisions Govern International Law in India?

Article 51(c) of the Constitution

Article 51 of the Constitution forms part of the Directive Principles of State Policy.

Article 51(c) provides that the State shall endeavour to foster respect for international law and treaty obligations in the dealings of organised peoples with one another.

Article 51 therefore demonstrates the constitutional importance attached to international law.

However, Article 51 is a Directive Principle of State Policy. It does not mean that every international treaty automatically becomes directly enforceable before Indian courts.

Article 253 of the Constitution

Article 253 gives Parliament power to make laws for implementing any treaty, agreement or convention with another country or countries, as well as decisions made at international conferences, associations or other bodies.

This provision is particularly important because it provides a constitutional mechanism through which international commitments may be implemented in India.

The Supreme Court also referred to Article 253 and Entry 14 of the Union List while explaining the relevance of international conventions to domestic law in Vishaka v State of Rajasthan.

Article 73 and Executive Power

Article 73 concerns the extent of the executive power of the Union.

The Supreme Court in Vishaka noted its relevance alongside Article 253, particularly in relation to matters in which Parliament has legislative competence.

The executive can therefore undertake international obligations on behalf of India within the constitutional framework, although alteration of existing domestic law may require legislation.

Are International Treaties Automatically Enforceable in India?

Generally, an international treaty does not automatically become enforceable as domestic law merely because India has entered into or ratified it.

Where implementation of a treaty requires changes to Indian law, restricts existing rights or creates domestic rights and liabilities requiring statutory authority, legislation is ordinarily necessary.

This principle was recognised in Maganbhai Ishwarbhai Patel v Union of India.

The constitutional question of domestic enforcement therefore needs to be distinguished from the broader law of treaties in international law, which deals with matters such as formation, validity, binding force, interpretation and termination of treaties at the international level.

A similar approach appears in Jolly George Varghese v Bank of Cochin, where the Supreme Court dealt with the relationship between an international covenant and existing Indian law. The case is frequently cited for the proposition that an international commitment does not, merely by itself, automatically become an enforceable part of Indian municipal law without the required domestic legal basis.

Can Indian Courts Use International Conventions?

Yes. International conventions can play an important interpretative role even where they have not been reproduced word-for-word in domestic legislation.

The leading decision is Vishaka v State of Rajasthan.

The Supreme Court was dealing with sexual harassment at the workplace at a time when there was no specific legislation comprehensively occupying the field. The Court held that international conventions and norms consistent with fundamental rights could be used in interpreting constitutional guarantees where domestic law contained a legislative vacuum.

The Court stated that an international convention not inconsistent with fundamental rights and harmonious with their spirit could inform the interpretation of those rights. It referred particularly to Articles 14, 15, 19(1)(g) and 21 of the Constitution.

Vishaka is therefore important because it shows that India’s dualist approach does not prevent international law from influencing constitutional interpretation.

What Is the Position of Customary International Law in India?

The position concerning customary international law is somewhat different from the position concerning treaties.

In Gramophone Company of India Ltd v Birendra Bahadur Pandey (1984), the Supreme Court recognised that rules of international law may be accommodated within municipal law where they do not conflict with Acts of Parliament.

The Court also explained that courts should, within legitimate limits, interpret municipal legislation in a manner that avoids conflict with well-established principles of international law. However, where a clear and unavoidable conflict exists, municipal legislation prevails before the national court.

Thus, customary international law may influence and become part of domestic law where it is compatible with existing Indian legislation.

Important Cases on International Law and Municipal Law in India

Is India Completely Dualist?

Describing India simply as a dualist country can hide important qualifications.

India broadly follows dualism where treaties are concerned because international treaty obligations do not invariably become enforceable municipal rules merely through ratification.

At the same time, Indian courts recognise several points of interaction between the two legal systems.

International conventions may assist in constitutional interpretation. Customary international law may be recognised where it does not conflict with domestic legislation. Courts may also prefer an interpretation of municipal law that is consistent with India’s international obligations where the statutory language permits such an interpretation.

The Indian approach can therefore be described as predominantly dualist in treaty implementation but receptive to international law in interpretation and in the recognition of compatible customary international principles.

Why Is the Relationship Between International and Municipal Law Important?

The relationship has become increasingly significant because modern international law extends into areas traditionally regarded as domestic matters.

Human rights conventions may affect constitutional interpretation. Environmental treaties may require national regulatory legislation. International trade agreements can require amendments to economic laws. Extradition treaties influence criminal cooperation. Intellectual property conventions may require changes to national intellectual property legislation.

International commitments therefore frequently depend upon domestic legislatures, executives and courts for practical implementation.

The distinction between international obligation and domestic enforceability also prevents confusion between two different questions: whether India is bound internationally and whether an individual can directly enforce that obligation before an Indian court.

These questions are related but are not always answered in the same manner.

Conclusion

The relationship between international law and municipal law explains how international legal obligations interact with the internal legal system of a State.

The two principal theories are monism and dualism. Monism considers international and municipal law as parts of a unified legal order, while dualism considers them separate systems and generally requires international rules to enter domestic law through appropriate constitutional processes.

India broadly adopts the dualist approach in relation to treaties. An international agreement may bind India internationally, but legislative implementation may be necessary where the agreement changes existing law or affects domestic rights and obligations.

The position is nevertheless flexible. Article 51(c) encourages respect for international law and treaty obligations, while Article 253 enables Parliament to implement international agreements through legislation. Indian courts have also relied upon international conventions in interpreting constitutional rights and have recognised compatible principles of customary international law.

Cases such as Maganbhai Ishwarbhai Patel, Jolly George Varghese, Gramophone Company of India, Vishaka and Union of India v Agricas LLP collectively demonstrate that international law and municipal law in India are neither completely merged nor completely isolated. They operate as distinct legal orders that continuously interact through constitutional provisions, legislation and judicial interpretation.

Note: This article was originally written by Srishti Sharma (Ideal Institute of Management and Technology) and published on 09 June 2020. It was subsequently updated by the LawBhoomi team on 21 September 2026.