Brownshirts
 Employees of the Tax Credits Office of Her Majesty's Revenue & Customs (HMRC). Derived both from their role as enforcers for Gordon Brown, and their enthusiastic embracing of Social Justice & Human Rights values not seen since the fall of Nazi Germany. 
'I don't believe it, love - the Brownshirts have just phoned demanding we pay all last years Tax Credits back or they'll take us to court'