Thatcher favourite, undone by the revelation of an affair

Cecil Parkinson, who has died aged 84, occupied important cabinet offices and was twice chairman of the British Conservative Party, but his career was all but destroyed by his affair with Sara Keays, his one-time secretary.

This cause célèbre finally compelled a reluctant Margaret Thatcher to return him to the back benches, only months after, as chairman of the party, he had played a crucial role in the Tories' landslide election victory of 1983.

The affair which was to haunt him virtually until his dying day ran counter to the then prime minister’s crusade for “family values”, and, although she reputedly had a soft spot for the tall, handsome and clean-cut Parkinson, she had no choice but to accept his resignation.

Thatcher was to restore him to the cabinet as energy secretary in 1987 after some four years “in the wilderness”. He was also to serve a second term as party chairman under William Hague.

Athlete

Cecil Edward Parkinson

, the son of a railway worker, won a scholarship to Royal Lancaster Grammar School and moved on from there to Emmanuel College, Cambridge, where he was a noted athlete. He became an accountant and businessman and a director of many companies.

He entered parliament in 1970 and four years later was made a whip by Edward Heath, but he made little effort to conceal his growing dislike for the political direction taken by the Heath government.

Thatcher appointed him minister for trade on her victory in 1979. Then, in 1981, she promoted him to paymaster-general and made him chairman of the party.

He was influential with Thatcher, a man after her own heart, who had progressed from a Lancashire working class background to become a self-made businessman.

His career looked to be unstoppable, and in 1983 Thatcher made him trade and industry secretary. But at the same time rumours began to spread around Westminster about the impending disclosure of an affair in which he was involved.

His eventual resignation, following a night of drama at the Tory party conference, came after Keays issued a statement on Parkinson’s alleged promise to marry her, leaving his wife, Ann.

Abortion

In a later book, she claimed that Parkinson had “begged” her to have an abortion and that he had “haggled over every pound” of support. He repeatedly claimed that he had voluntarily made more than adequate provision for Keays and their daughter, Flora.

When in 1988, Flora underwent an operation for a brain tumour thought to cause epilepsy, his maintenance for the child was increased from £3,000 a year to £10,000. During his period out of government – during which Miss Keays used many opportunities to remind him, uncomfortably of his past – Parkinson was hit by another personal calamity when one of his three daughters developed a heroin addiction.

When John Major became prime minister, Parkinson handed in his resignation, and he stepped down from parliament in 1992. From the Lords, he occasionally sniped at Major, claiming that natural Tory voters felt "let down, even betrayed". In general, however, he remained a loyal Conservative, though never afraid to speak out on issues close to his heart, such as his deep suspicion of the European Union.

He is survived by Ann and three daughters, Mary, Emma and Joanna.