The information requested as to how many were permitted to retain citizenship since 2005 could be obtained by the detailed examination of individual records only at disproportionate cost. Although no one has been deprived of British citizenship, on the basis that that status was acquired on the basis of fraud, since 2005, the UK Border Agency has recently implemented a new deprivation policy and is pursuing deprivation action in a number of cases.
As regards indefinite leave to remain, a person who obtains (or seeks to obtain) leave to remain by deception is liable to removal under section 10 of the Immigration and Asylum Act 1999. We do not however have records for those that have been identified as using deception but have none the less been allowed to retain their indefinite leave to remain, as these could be obtained by the detailed examination of individual records only at disproportionate cost.