Born in Dublin to William Traven Aitken (himself a Conservative MP) and Lady Penelope Aitken (daughter of the first Baron of Rugby), he attended Eton College and read law at Christ Church College, Oxford. He served as a war correspondent during the 1960s in Vietnam and Biafra.
He was returned as MP for Thanet East in the 1974 General Election. He managed to offend Margaret Thatcher by ending a relationship with her daughter, Carol Thatcher, and suggesting that Thatcher "probably thinks Sinai is the plural of Sinus" to an Egyptian newspaper. He stayed on the backbenches throughout Thatcher's reign, eventually becoming Minister of State for Defence Procurement under John Major in 1992.
He became Chief Secretary to the Treasury in 1994, a Cabinet position, but resigned in 1995, to defend himself against accusations that whilst Minister of Defence Procurement he violated ministerial rules by allowing an Arab businessman to pay for his stay in the Ritz hotel in Paris.
His libel action against the Guardian newspaper and Granada Television collapsed in June 1997 (a month after he had lost his seat in the 1997 General Election) when the Guardian produced evidence that his claim that his wife, Lolicia Aitken, paid for the stay could not possibly be true.
After the collapse of the trial, he was charged with perjury and perverting the course of justice, and in 1999 was jailed for 18 months (of which he served 7 months). He was unable to cover legal costs and was declared bankrupt.
His sister is the actress, Maria Aitken.