Tag britains most senior counter terror police officer

I'm assuming you're referring to the most senior counter-terrorism police officer in the United Kingdom. According to various sources, the current most senior counter-terrorism police officer in the UK is:

Assistant Commissioner Neil Basu

Neil Basu is the Assistant Commissioner for Specialist Operations at the Metropolitan Police Service (Scotland Yard) in London. He has been in this role since 2018 and is responsible for leading the Met's Counter Terrorism Command (SO15).

Prior to his current role, Basu was the Deputy Assistant Commissioner for Specialist Operations and has also served as the Head of Counter Terrorism Command (SO15) from 2014 to 2018.

Basu has been involved in several high-profile counter-terrorism investigations and operations, including the Manchester Arena bombing in 2017 and the London Bridge attack in 2017.

Please note that the most senior counter-terrorism police officer may change over time, and this information may not be up-to-date in the future.