The Special Demonstration Squad (SDS) was an undercover unit of Greater London's Metropolitan Police Service (MPS or the Met), set up in 1968 with the approval of the Wilson government,[1] to infiltrate British protest groups.[2][3][4] It was part of the Special Branch, and worked closely with the Crown Prosecution Service (CPS).[5] It operated from 1968 to 2008.[6]
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was invoked but never defined (see the help page).