Anti-terrorism, Crime and Security Act 2001

The Anti-Terrorism, Crime and Security Act 2001 or ATCSA is a British Act of Parliament introduced as emergency legislation after the September 11, 2001 attacks in New York. It was criticised in the press at the time as being opportunistic and mainly containing powers that were rejected from the Terrorism Act 2000.

One of the more notable powers in ATCSA is the suspension of habeas corpus for non-British citizens suspected, by the Home Secretary, of terrorist offences. At the time of writing, several men are being detained without charge at HMP Belmarsh under the provisions of this Act.