LONDON, Oct. 6 (Xinhua) -- Britain's under-fire Prime Minister Theresa May was facing a fight for her political life Friday with a growing number of her own MPs said to favor a challenge to her leadership.

A former chairman of May's governing Conservative Party has emerged as a ringleader in the call for a new occupant at 10 Downing Street.

The MP and former minister, Grant Shapps, said in media interviews Friday he had the support of about 30 Conservative MPs, including five former cabinet ministers.

Although May's closest ministers in her governing cabinet have pledged their support for her, Shapps claimed some of her cabinet ministers privately agreed with his call.

In her first reaction to the day's developments Theresa May said she has the "full support of her cabinet". The BBC quoted May as saying the country needed "calm leadership" adding: "That's what I'm providing."

The party's poor showing in the June snap election when May lost her overall majority in the House of Commons had already weakened her position.

But the fiasco of her disastrous speech at this week's party conference has placed a great threat to her continued leadership. May's coughing fits which continually interrupted her speech, a prankster breaching security to approach her on the conference platform with the conference backdrop falling apart making it a triple disaster played out live on television.

The big question now will be whether enough backbench Conservative MPs sign a letter calling for a leadership election. It would mean around 48 MPs, 15 percent of the total number in the House of Commons, having to back a challenge to May by saying they had lost confidence in her leadership.

Shapps said in media interviews: "I believe Theresa May is very decent person and unfortunately fought an election that didn't work out. We've not really managed to see that relaunch.

"There's that sort of lack of discipline in the cabinet and party conference this week and I think a growing number of my colleagues realize the solution isn't to bury our heads in the sand and hope things will get better."

Shapps told Sky News those calling for May to go want her to step down of her own volition rather than be forced out.

Environment Secretary and one-time leadership contender Michael Gove, threw his weight behind May. In a morning radio interview Gove said: "No one is burying their heads in the sand. The critical thing is the PM (May) has been doing a fantastic job. She showed an amazing degree of resilience and courage this week, of a piece with the fantastic leadership she's shown throughout the time she has been prime minister.

"The truth is the overwhelming majority of Conservative MPs, the truth is the entirety of the cabinet, the truth is the overwhelming majority of people, want the prime minister to concentrate on doing the job that 14 million people elected her to do earlier this year."

Writing in the Daily Telegraph, British Home Secretary Amber Rudd pleaded with May not to resign as prime minister, saying Britain has reached a turning point as a nation.

According to various media reports, supporters of the plot to oust May believe they could reach the required number early next week when parliament re-opens after the conference season.

So far May has remained at 10 Downing Street with no planned engagements, recovering from the illness that she suffered throughout her conference week.

The drama will be played out in what is known as the 1922 Committee, the body that represents back bench MPs in the House of Commons.

Charles Walker, vice chairman of the committee, told the BBC: "What you're seeing here is probably the coalition of the disappointed people who think that their brilliant political talents have not been fully recognized, and really it doesn't reflect well on them."

The uncertainly around May's future led to a fall in the value of the sterling on Friday, with the pound worth around 1.30 U.S. dollars.