Iain was born in April 1954. He was educated at Dunchurch College of Management, the Royal Military Academy in Sandhurst, the Universita per Stranieri in Perugia, Italy and HMS Conway in Anglesey.

Iain was elected as Member of Parliament for Chingford at the 1992 General Election. In 1997, he was re-elected for the re-drawn constituency of Chingford and Woodford Green.

Under William Hague, Iain was promoted to the Shadow Cabinet in 1997 and was promoted to Shadow Defence Secretary in 1999. Over the next two years, Iain gained an international reputation for his contribution to the debates on the European Army and the US missile defence initiative as well as his success in exposing the Government's failure to give British forces the right money and equipment.

In September 2001, at the age of 47, Iain was elected Leader of the Conservative Party in the first ever ballot of the Party's membership. He served as Leader until November 2003.

In December 2005, he was appointed Chairman of the Party's new Social Justice Policy Group.