In 1984 Michael won the by-election in Enfield Southgate, he joined the Government in 1986, and remained a member until 1997. As a Cabinet Minister was Chief Secretary to the Treasury, Secretary of State for Employment, and Secretary of State for Defence. He was admitted to the Privy Council in 1992.
After his 1997 electoral defeat, Michael turned to journalism. He had a weekly column in The Scotsman. He had a three part series for Channel 4 about politics Portillo’s Progress, and a programme in BBC2’s Great Railway Journeys series, which was partly a biography of his late father, and radio programmes on Wagner and the Spanish Civil War.
Michael was re-elected to Parliament 1999 and was Shadow Chancellor of the Exchequer February 2000 – September 2001.
For six years he was a weekly columnist on The Sunday Times and was the theatre critic of The New Statesman between 2004 and 2006.
Michael was a member of the International Commission on Missing Persons in the former Yugoslavia (which organises the identification of massacre victims) from 1998 to 2012. He sat on of the Board of BAE Systems plc from 2002 to 2006.
In 2008 he chaired the judges of the Man Booker prize, in 2011 he chaired the Art Fund Prize and in 2012 he chaired the committee recommending grants for endowment to arts and heritage institutions under the government’s Catalyst programme.