The government of the UK is not allowed to remove the citizenship of a UK citizen if doing so would make them stateless. The government of the UK claims that removing the citizenship of Shamima Begum would not render her stateless, because she would be entitled to claim citizenship of the People’s Republic of Bangladesh, on account of the fact that her parents are originally from the territory of that state.
When first I heard of this argument, I realised that, like many other people in Britain, I am now a second-class citizen of the UK. In theory, I am entitled to claim citizenship of another state, on account of the origins of my late mother. Thus, if I displease the Home Secretary, I could be stripped of my UK citizenship.
Anyone with a Jewish grandmother could be stripped of their UK citizenship, on the grounds that they are entitled to become a citizen of the State of Israel
Anyone with an Irish grandparent could be stripped of their UK citizenship, on the grounds that they are entitled to become a citizen the Republic of Ireland.
However, someone who incurred the displeasure of the Home Secretary who was not entitled to the citizenship of another state could not be stripped of their UK citizenship.