“Following widespread concerns about the expenses claimed by some MPs and some members of the House of Lords, a number of complaints were made to the Metropolitan Police alleging criminal conduct. In light of these complaints on 15 May 2009, the Commissioner of the Metropolitan Police, Sir Paul Stephenson, and I agreed to set up a panel of senior police officers and senior prosecuting lawyers to assess the complaints and consider whether there should be a criminal investigation into any of them.”
Crown Prosecution Service, 5th February 2010
Source: www.cps.gov.uk