He remained an MP after quitting the government when Mr Blair left office and will replace Manchester Central MPTony Lloyd as the British representative on the Parliamentary Assembly of the Council of Europe.
Jeffrey Donaldson MP will travel to London with the Ulster Unionist Party delegation to meet the UK Prime Minister TonyBlair and the Irish Taoiseach Bertie Ahern.
Others who have resigned as an MP by being appointed to the Chiltern Hundreds include Roy Jenkins, Brian Walden, Neil Kinnock, TonyBlair, David Davis, and Eric Illsley.