Two parliamentary by-elections have been triggered after Labour MPs Alun Michael and Tony Lloyd stood down from the House of Commons to fight for election as police and crime commissioners.
The Treasury announced that Mr Michael had been appointed to the Chiltern Hundreds and Mr Lloyd to the manor of Northstead - the formal process by which they cease to be MPs.
Mr Michael will be Labour's candidate for police and crime commissioner in South Wales and Mr Lloyd in Greater Manchester for the elections to be held on November 15.
Their departure triggers by-elections in Mr Michael's Cardiff South and Penarth seat and Mr Lloyd's Manchester Central constituency, both of which were held by Labour by comfortable majorities in the 2010 general election.
Under parliamentary procedures, an MP cannot simply resign his or her seat, but can leave Parliament by taking up the nominal Crown appointment of steward and bailiff to either the Chiltern Hundreds or the manor of Northstead.