An individual who is subject to an EU travel ban is not normally permitted to enter the UK. An exemption can be agreed in respect of a person whose presence in the UK is required, for example as a witness, to further the cause of peace or for humanitarian reasons. In such cases an assessment of the risks posed to the UK and public by the individual would be made in conjunction with law enforcement and security agencies. Depending on that assessment appropriate measures would be taken to monitor the individual while here.
A person subject to an EU travel ban is excluded from the UK and details of all those individuals included on a travel ban are entered on the Home Office watch list. That watch list is used by staff overseas and at UK ports to identify those people who should not be admitted to the UK. A person who entered the UK by deception and so in breach of a travel ban would be treated as an illegal entrant and be subject to removal. We have no record of any individual who is subject to a travel ban being identified in the UK and being either arrested or deported.
The UK is only party to EU and UN travel bans and the enabling immigration legislation only allows the Secretary of State to designate EU or UN travel bans. Such designation has the effect of making individuals subject to such bans automatically excluded from the UK under section 8B of the Immigration Act 1971.
There is no international immunity from the effects of an EU travel ban. I can also confirm that individuals subject to an EU travel ban are not permitted to transit the UK.
The Home Office has not received any representations from people subject to EU travel bans. The Foreign and Commonwealth Office has received only one formal representation but does receive a number of informal, and not centrally recorded, representations from those who are subject to EU travel bans.