Former Welsh secretary Dame Cheryl Gillan has passed away at the age of 68 after a lengthy illness, the Conservative Party has confirmed.
The Prime Minister said the former cabinet minister would be “sorely missed” and described her as a “great servant”.
“I’m very sad to hear the news of the death of Dame Cheryl Gillan,” said Boris Johnson.
“She was a great servant to the people of Chesham and Amersham, to the Conservative Party and to the country as secretary of state for Wales.
“Always full of wise advice and good humour, she was much loved on all sides of the House of Commons and will be sorely missed.
“My sincere condolences to her family and friends.”
Former Tory prime ministers Theresa May and David Cameron both tweeted their condolences, with Mrs May stating she was “so saddened to hear that my good friend has passed away”.
An MP since 1992, co-chairman of the Conservative Party Amanda Milling said the noted anti-HS2 campaigner had made a “huge contribution to public life”.
“It was incredibly sad to hear that Dame Cheryl Gillan MP passed away at the weekend,” said Ms Milling.
“Cheryl had been ill for some time, but battled her illness with great stoicism and grace.
“Cheryl was a dedicated parliamentarian for many decades, serving in the cabinet and she made a huge contribution to public life and our party.
“Our thoughts and prayers are with Cheryl’s family and friends.”
Dame Cheryl found herself centre stage of Tory politics when she was acting joint chair of the influential 1922 Committee of backbench MPs from May to September 2019.
She helped preside, along with Charles Walker MP, over the Tory leadership contest to elect a successor to Mrs May – a contest Mr Johnson won.
The runner-up in that contest, former foreign secretary Jeremy Hunt, joined in paying tribute to the ex-marketing executive.
“So sad to hear we have lost Cheryl Gillan, one of the warmest and most generous hearted people in the House of Commons,” said the chairman of the Commons Health Committee.
“She was a formidable campaigner for autistic people but also the definition of British stoical good humour – an enormous credit to her party and to Parliament.”
Former minister Tracey Crouch, who has been embroiled in her own struggle with breast cancer in recent months, said she was “heartbroken” at the news.
The Tory MP described Dame Cheryl as a “great source of strength as we went through chemo together”.
“When she told me she was dying I told her all the nice things I would say so she knew she was an incredibly inspirational woman in politics who fought for the things she believed in,” Ms Crouch tweeted.
“She was always kind and helpful to us newbies. She had oodles of wisdom from her years as an MP which she shared willingly. I shall miss her greatly.”
There were cross-party condolences, with Labour leader Sir Keir Starmer fondly recalling his dealings with the senior Conservative “on a number of issues”.
He said: “She was respected across the House and a great champion for her constituents.”
Speaker of the House of Commons Sir Lindsay Hoyle said: “Dame Cheryl Gillan was one of the most popular, friendly and kindly people in the House of Commons, so her passing leaves a big hole in all our lives.
“She was someone who drew people to her because of her warm, sunny disposition and good sense of humour.”
One of Dame Cheryl’s final contributions in Parliament was her legislative bid to make it easier to test offenders in prisons for new forms of drugs.
Her Prisons (Substance Testing) Bill is still progressing through the House of Lords, having cleared the Commons last month.
Dame Cheryl was unable to participate in its final stages in the Commons in March, with Conservative colleague Richard Holden moving the Bill on her behalf.
Deputy Speaker Dame Eleanor Laing, after the Bill had cleared the Commons, told MPs it was “very sad” Dame Cheryl could not be with them in the chamber but their support for the Bill would mean a “very great deal” to her.