Clapham is a left-winger and was a member of the Socialist Campaign Group, rebelling against the government on various issues. He was a member of the Trade and Industry Committee from 1992 to 1997 and again from 2003; in between he was Parliamentary Private Secretary to Alan Milburn following the 1997 general election, but he resigned over Harriet Harman's decision to cut lone parent benefits in December of that year. He used to be very loyal to his old boss Arthur Scargill, but later criticised him for being too Stalinist.