Fundamental Right No. 12: Protection Against Retro…
By Muhammad Imran, Staff Member, SAHSOL-LUMS and Asma Rahmat, Final Year Law Student, SLC, Superior University and Muhammad Ameer Hamza, Final Year Law Student, SLC, Superior University
Article 12 of the Constitution of the Islamic Republic of Pakistan, 1973, enshrines one of the oldest and most celebrated principles of criminal jurisprudence, namely nullum crimen, nulla poena sine lege, which means there can be neither a crime nor a punishment without prior law. This constitutional guarantee embodies the rule of law by prohibiting retrospective criminal legislation and protecting every individual from arbitrary prosecution or punishment. It ensures that a person may be held criminally liable only for conduct that constituted an offence under the law at the time it was committed, and that no punishment more severe than that then prescribed may subsequently be imposed.
The first part of Article 12 prohibits the retrospective creation of criminal offences. A person cannot be convicted for an act or omission which was lawful when committed merely because the legislature subsequently criminalises that conduct. The second part prohibits the retrospective enhancement of punishment. Accordingly, where the law prescribes a maximum sentence of six months’ imprisonment or two years’ imprisonment at the time of the offence, neither the judiciary nor the legislature may subsequently impose or authorise a more severe penalty for that completed act. The constitutional guarantee thus preserves legal certainty, protects legitimate expectations, and prevents arbitrary exercises of legislative and executive power.
Article 12 is founded upon the universally accepted doctrine of legal certainty, which requires that criminal laws be clear, prospective, and predictable. Individuals must be capable of regulating their conduct according to existing law without fear that future legislation will retrospectively criminalise their past actions or increase their punishment. The principle therefore operates as an indispensable safeguard against governmental arbitrariness and political persecution and constitutes a cornerstone of every constitutional democracy governed by the rule of law.
The constitutional philosophy embodied in Article 12 is consistent with internationally recognised human rights norms. Article 11(2) of the Universal Declaration of Human Rights, 1948, provides that no person shall be held guilty of any penal offence on account of any act or omission that did not constitute a penal offence under national or international law at the time it was committed, nor shall a heavier penalty be imposed than that applicable at the time of the commission of the offence. Likewise, Article 15 of the International Covenant on Civil and Political Rights (ICCPR), to which Pakistan is a State Party, reiterates the same prohibition against retrospective criminal liability while recognising only the limited exception relating to offences recognised under the general principles of international law.
Comparable constitutional protection is also found in the United States Constitution, where Article I, Sections 9 and 10 expressly prohibit Congress and the States from enacting ex post facto laws. This prohibition has long been regarded as a fundamental limitation upon legislative authority and reflects a universal constitutional commitment to fairness in criminal justice.
The superior courts of Pakistan have consistently treated Article 12 as an indispensable constitutional safeguard. In Mian Muhammad Nawaz Sharif v. The State, the Supreme Court reaffirmed that Article 12 embodies the constitutional prohibition against retrospective penal legislation and protects individuals from being subjected to criminal liability or enhanced punishment under laws enacted after the commission of the alleged offence. The Court emphasised that retrospective penal laws offend the rule of law because criminal consequences must always be determined according to the law in force at the relevant time. Similarly, in Benazir Bhutto v. Federation of Pakistan, the Supreme Court underscored that fundamental rights must receive a liberal and purposive interpretation so as to prevent arbitrary governmental action and preserve constitutional liberties. Although that case did not directly concern Article 12, its interpretative philosophy has significantly influenced the constitutional protection afforded to penal safeguards.
A significant constitutional question concerns the offence of high treason under Article 6 of the Constitution. High treason, comprising the abrogation, subversion, suspension, or holding in abeyance of the Constitution, represents the gravest constitutional offence. Through the Constitution (Eighteenth Amendment) Act, 2010, Parliament expanded Article 6 to include persons who aid, abet, collaborate with, or validate such unconstitutional acts. Nevertheless, Article 12 continues to apply with full constitutional force. Even in prosecutions for high treason, criminal liability and punishment cannot be imposed retrospectively. Any legislative amendment increasing punishment or enlarging criminal liability can operate only prospectively and cannot constitutionally affect acts committed before its enactment.
The historical experience of constitutional development further demonstrates the importance of this principle. Following the restoration of the English monarchy, the remains of Oliver Cromwell were exhumed in 1661 upon the orders of Charles II, symbolically hanged, beheaded, and publicly displayed. Although this episode belonged to a different constitutional era, it illustrates the dangers of political vengeance unconstrained by constitutional guarantees. Modern constitutional democracies reject such practices and instead insist that criminal justice must always be governed by legality, due process, and prospective application of penal laws.
Article 12, therefore, is not merely a procedural safeguard but a substantive manifestation of constitutionalism itself. It preserves the supremacy of law over arbitrary power, protects individual liberty against retrospective criminal legislation, and strengthens public confidence in the fairness and integrity of the criminal justice system. Together with Articles 4, 9, and 10A of the Constitution, it forms an integral part of Pakistan’s constitutional architecture for the protection of human dignity, legal certainty, and the rule of law.
Article 12 of the Constitution of the Islamic Republic of Pakistan, 1973, is a cornerstone of constitutionalism and the rule of law. By prohibiting retrospective criminal legislation and the retrospective enhancement of punishment, it embodies the fundamental principle of nullum crimen, nulla poena sine lege, ensuring that no person is punished except in accordance with the law in force at the time of the alleged offence. In conjunction with Articles 4, 9, and 10A, Article 12 protects legal certainty, due process, and individual liberty while preventing arbitrary or politically motivated prosecutions.
The superior courts of Pakistan have consistently recognised that Article 12 is not merely a procedural safeguard but a substantive constitutional guarantee that restrains the arbitrary exercise of State power. Its effectiveness, however, depends upon strict constitutional compliance by all organs of the State. Parliament must refrain from enacting retrospective penal laws, while the judiciary should continue to interpret Article 12 purposively to uphold the principles of legality and fairness. Regular constitutional training for judges, prosecutors, investigators, and law enforcement agencies, together with greater public awareness of fundamental rights, would further strengthen its practical implementation.
Pakistan should also continue to harmonise its criminal justice framework with international human rights standards, particularly the principle of legality embodied in the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights. Above all, no political necessity or public pressure should ever justify departure from the constitutional prohibition against retrospective punishment. By faithfully preserving Article 12, Pakistan reinforces constitutional supremacy, safeguards human dignity, and affirms that the rule of law—not political expediency—must remain the ultimate foundation of justice.
