Michael Ancram, a former deputy leader of the Conservative Party, has died at the age of 79, his family said.
A family statement said the 13th Marquess of Lothian, as he was formally known, died in hospital in the early hours of October 1 after a short illness.
He also served as shadow foreign secretary and had been a member of the House of Lords since 2010, in a political career spanning five decades.
Ancram was first elected as an MP for Berwickshire and East Lothian in 1974 but lost his seat in a snap election eight months later.
He returned to Parliament after defeating future Labour prime minister Gordon Brown for the Edinburgh South constituency five years later, before going on to serve as MP for Devizes from 1992 to 2010.
On retiring from the House of Commons, Ancram joined the House of Lords in November 2010 by virtue of a life peerage, Baron Kerr of Monteviot.
Scottish Conservative leader Russell Findlay said: “I am sorry to hear of the passing of Michael Ancram, who was a first-rate politician and a gentleman.
“The thoughts of all in the Scottish Conservatives are with his wife and family.”
Lord Donald Cameron, a former Scotland Office minister and former MSP, said his uncle, Michael Ancram, had been “a huge support and inspiration”.
“Some very sad news tonight,” he said on social media site X.
“Michael was a man of great warmth, humour and generosity.
“As an uncle, he was a huge support and inspiration to me.
“We will all miss him very much. Eternal rest grant unto him.”
Jackson Carlaw, who briefly led the Scottish Tories in 2020, described Mr Ancram as “a politician of charm, principle and duty” who had “served our country with distinction”.
Follow STV News on WhatsApp
Scan the QR code on your mobile device for all the latest news from around the country