Powers and constraints
Citizenship deprivation on the basis of behaviour is a power that has existed in statute since 1918. Despite Parliament legislating to make it increasingly easier for the executive to make use the power in 2002 and 2006, it remained virtually unused
until 2010. Suddenly, though, citizenship stripping came into fashion by means of not just the statutory power but also an obscure common law power called nullification. The Supreme Court put a stop to routine use of the nullification power at
the end of 2017 in the case of R (Hysaj) v Secretary of State for the Home Department  UKSC 82 but the use of the deprivation power has only grown.
Before 2010, official statistics record ‘less than five’ British citizens per year had their citizenship taken from them. That had increased to over 20 by 2014 and then over 100 by 2017.
The test for whether British citizenship can be taken away from an individual has been, since 2006, broadly whether it is considered ‘conducive to the public good’ to do so. This is an exceedingly broad power directly comparable to the
power to deport foreign nationals. It might well be thought that the legal test for taking away citizenship ought to be stronger than for deporting a foreign national, but not so. In 2018 the Home Secretary Sajid Javid announced at the Conservative
Party Conference that he would make more extensive use of the power in cases of serious criminality as well as in national security cases.
There is a constraint on the deprivation power, though. It cannot generally be used where the person concerned would be left stateless as a consequence. This is because the UK is a signatory to the UN Convention on Statelessness.
Arguments against deprivation
There are two main arguments against the use of citizenship deprivation. The first is broadly that of Voltaire; that by exiling citizens we merely throw into a neighbour’s field the stones which incommode us in our own. In a deprivation case
such as the Supreme Court case of Pham (Appellant) v Secretary of State for the Home Department  UKSC 19, why should Vietnam, a country Mr Pham left aged 6, be forced to accept back a citizen who grew up and was radicalised in the United
In Shamima Begum’s case, why should Bangladesh, a country the UK asserts she is a national of, be forced to admit her when she was not born there, has perhaps never visited and has no real connection other than through her parents? She was born
in the UK and grew up in the UK; is she not therefore the UK’s responsibility?
"Cases like that of Shamima Begum perhaps suggest it is time to overhaul antiquated treason laws so that Parliament can debate this deadly serious subject and clear thresholds can be established."
Some argue she should be returned to the UK and face trial if she has broken any UK laws. It is not clear from the limited publicly available information whether she might arguably have committed any crime. Trial for treason has been suggested by
some and might well be a more appropriate way to punish disloyal actions than citizenship deprivation. The UK’s treason laws are so archaic now that prosecution is generally considered impossible, or at least impolitic. Cases like that of
Shamima Begum perhaps suggest it is time to overhaul antiquated treason laws so that Parliament can debate this deadly serious subject and clear thresholds can be established.
The second argument against deprivation of citizenship is that only some British citizens can generally be deprived of their citizenship: those who have another nationality to fall back on. Sometimes this might be because they have subsequently voluntarily
acquired another nationality, or perhaps because they naturalised as British and retained their original nationality. In a considerably larger number of cases, it is because the person concerned has in effect inherited a nationality from a parent.
British nationality law certainly works in this way, automatically making British any child born abroad to a British citizen parent whether the parent or child likes it or not or even knows it or not.
Some other countries have nationality laws that work similarly, automatically making some children citizens. Other countries require a child to be registered before the child becomes a citizen. Whether a British child born in the UK can be stripped
of their British citizenship therefore depends on whether he or she has a foreign national parent and how the nationality laws of the parent’s country operate. This is, not to put too fine a point on it, random. Some can be stripped of their
citizenship and others cannot, and black and ethnic minority children are more likely to be eligible for citizenship deprivation than others.
Dangers of a divisive message
Citizenship stripping is therefore opportunistic rather than principled and it is more likely to be used against black and ethnic minority citizens. The message that this sends to communities, both minority and majority, is a divisive one. Some citizens
are more equal than others.