The former Conservative Cabinet minister Lord Gilmour of Craigmillar has died aged 81.
His eldest son David Gilmour said he died at the West Middlesex Hospital following a short illness.
Ian Gilmour served as defence secretary in Edward Heath's government in the 1970s and later as Lord Privy Seal in Margaret Thatcher's first government.
On the liberal wing of the Tory Party, the aristocratic Sir Ian Gilmour, as he was then, cut an uneasy figure in Mrs Thatcher's administration.
Dubbed the "wettest of the wets", in 1981 he became the first minister to be sacked by her. He responded by issuing a statement declaring that she was steering "full speed ahead for the rocks".
He remained a trenchant critic of her monetarist politics.
Before entering Parliament as MP for Central Norfolk in 1967, he was editor and proprietor of The Spectator magazine from 1954 to 1959.
The magazine's current editor, Matthew d'Ancona, said he was "deeply saddened" to learn of his death.
"He was a true Spectator legend and remained deeply interested in its fortunes," Mr d'Ancona said. "It was always a pleasure to receive a letter from him on this or that matter. He showed that he understood all that is best in British journalism to the last."
Lord Gilmour leaves four sons and a daughter.
