Amid the clash of arms in the UK about BREXIT and the free movement of EU citizens, one context remains unconsidered. Free movement of persons is not simply something provided for by the EU treaties to EU citizens and their family members, something of benefit to the stereotypical Polish plumber, the Bulgarian academic, or the clever and ambitious Italian journalist, who come to the UK in reliance on EU rights, it is also a human right.

Moving from one place to another is an ordinary human activity, undertaken by individuals and groups in furtherance of ordinary human goals: work, study, love, family reunion, protection and even curiosity. Migration (like settlement) forms part of ordinary human activity both within a state and between states. In that context to move freely, to take oneself away from one place and move to another, is a way for a person to find fresh opportunities, transform and remake herself, and develop potential that might otherwise be unrealised.

It is also a political act. Unhappy for any reason with a particular, government, politics or society, perhaps one of the most radical acts a person can do is simply to get up, leave and go elsewhere. If free movement begins anywhere, it begins in what may be thought of as a natural right (that is as a part of natural law) for a person to remove herself from a place inimical to her interests and go somewhere else, somewhere more promising. Unsurprisingly, political parties and movements (of left and right) that seek radical transformation of their societies have often been hostile to the exercise of free movement and are inclined to support border controls both as regards their own nationals and as regards alien migrants.

Free movement as a human right has been given positive effect in a number of international treaties and conventions. Some of these provisions are the Cinderellas of human rights instruments, hitherto unloved, yet perhaps destined to shine at the Ball of public debate as the salience of migration as a political subject continues to grow. In the UN International Covenant on Civil and Political Rights (ICCPR), free movement is provided for in Article 12, which concerns free movement within states and also between them. The United Kingdom has ratified the ICCPR and is bound it on the plane of international law, yet has not sought to transpose it into domestic law so that its provisions are of direct effect and justiciable before domestic courts.

Regarding free movement between states, Article 12(2) provides that ‘Everyone shall be free to leave any country, including his own’. However, on the other side of the medal struck for such virtuosity, there is no reciprocal right for everyone to enter any country. The principle of state sovereignty and the realities of the modern state system intrude on to the scene, inhibiting such innovation. Article 12(2) governs exit from a state, regardless of whether it is for temporary or more enduring purposes. In addition, it has been used to challenge refusal by a state to issue passports and travel documents to its own nationals. There have also been challenges to delays in issuing such documents and to the practice of charging persons to leave a country.

Article 12(3) while prohibiting certain restrictions on free movement, does not prohibit those restrictions provided for by law, and that are necessary to protect national security, public order, public health or morals or the rights and freedoms of others, where such restrictions are consistent with the other rights recognised elsewhere in the ICCPR. Thus there is plenty of scope for the energetic legislator or minister to peg back the exercise of the rights through lawful limitation, for example to compel military service or the attendance of an accused person at her criminal trial. However a ban on a woman leaving a country unaccompanied by a male relative, would offend rights protected elsewhere in the ICCPR and thus be contrary to Article 12(3).

Article 12(4),without qualification, provides that no-one shall be arbitrarily deprived of the right to enter his own country. By necessary implication, there is a prohibition on expulsion from one’s own country on the same basis. A person’s ‘own country’ is commonly that of her nationality but may also be extended to certain long-term residents, especially stateless persons, with a high level of attachment to a state. Article 12(4) regulates a state’s ability to deprive its nationals of its nationality, to exile them and to prohibit them from returning.

Despite its scope, Article 12 does not confer a right on an aliento enter a state. Nor does it grant a right of residence to such a person if she is permitted to enter. What it does do is provide everyone with a right to leave a country (subject to lawful exception) and prohibit arbitrary deprivation of a person’s right to enter her own country.

Article 12 ICCPR, should be viewed together with Article 13 ICCPR, which provides that an alien lawfully in the territory of a state may be expelled only in pursuance of a lawful decision and shall, except where compelling reasons of national security otherwise require, be allowed to submit the reasons against his or her expulsion and to have his or her case reviewed by, (and be represented for the purpose before) a competent authority or a person or persons designated by the same. Only lawfully present aliens are protected and even they may be expelled where a lawful decision is made to effect their expulsion. True it is that they enjoy a measure of procedural protection but so much depends on how that protection is implemented and on what provision the substantive law makes, that little comfort may be derived from such protection in many cases.

The universal provision for free movement found in the ICCPR, finds its analogue in many regional instruments, for example the 4th and (Article 1 of the) 7th Protocols of the European Convention on Human Rights (NB the UK is not bound by either) and Article 22 of the American Convention on Human Rights. Looking at these instruments, both universal and regional, it is clear that free movement is a subject of concern for international law, that its operation is limited by public policy considerations, and that free movement is such a part of ordinary life that its incidence is understood as requiring protection as a human right.