[holding answer 1 May 2009]: None. There is no power of arrest under the Terrorism Act 2006. Any arrest for terrorism offences would be under either the Terrorism Act 2000 or other legislation.
Details of the number of arrests for terrorism offences between 11 September 2001 and 31 March 2008 are contained in the Home Office Statistical Bulletin:
“Statistics on Terrorism Arrests and Outcomes Great Britain 11 September 2001 to 31 March 2008” at:
http://www. homeoffice.gov.uk/rds/pdfs09/hosb0409.pdf
Details of the numbers of people arrested for a terrorism offence who have subsequently been deported are not available.