United Kingdom Supreme Court, [2021] UKSC 7, 26 February 2021 (Begum)

Revocation of citizenship and consequent expulsion for terrorism-related crimes. Possibility to re-enter the United Kingdom in order to have a fair trial. 

Art. 6 ECHR
British Nationality Act 1981 (UK)
Immigration Act 2014 (UK)

1. A person charged with terrorism crimes who was deprived of his/her British nationality does not have a right to re-enter the British territory in order to challenge the revocation order adopted by the Secretary of State for the Home Department. 

2. If national security grounds prevent a fair trial, the right to a fair trial of the concerned individual must be considered suspended until when there is no longer a risk for national security. 

3. On national security issues, courts have to respect the discretionary powers of Executive bodies (in that case, the Secretary of State for the Home Department). Consequently, if a person has been declared a threat to national security, courts can only review the Secretary of State's decision when it is manifestly irrational. 

The same case had been decided by the Special Immigration Appeals Commission and by the England and Wales Court of Appeal. 

Special Immigration Appeals Commission, T2/2020/ 0644, 7 February 2020. 
England and Wales Court of Appeal, Begum v. Secretary of State for the Home Department and Others, [2020] EWCA Civ 918, 16 July 2018. 

The United Nations Special Rapporteur on Counter-Terrorism intervened in the proceeding before the UK Supreme Court, submitting a brief.