Grant Shapps, a former party chairman, said “a growing number of people feel it’s time to make a change” after a poor election result and a disastrous conference speech by May earlier this week.
The number of rebels falls short of the 48 lawmakers needed to trigger a formal leadership challenge under party rules, but the plot further rattles May’s shaky grip on power.
May became prime minister through a Conservative leadership contest when David Cameron resigned in the wake of Britain’s June 2016 vote to leave the EU. Since then she has struggled to unite a government that is divided over how the country should leave the EU and what relationship it wants with the bloc after Brexit.
May was further weakened when she called a snap election for June that saw the Conservatives reduced to a minority government. A speech on Wednesday designed to reinvigorate the party descended into disaster as May was interrupted by a prankster and almost silenced by a sore throat, before letters began dropping off the slogan behind her.
In recent weeks Foreign Secretary Boris Johnson has gone public with his own plans for Brexit, a move widely seen as a challenge to May.
Shapps told Sky News that May is “a very decent woman” but without a new leader “we may be in a holding pattern which may be an ever-descending one.”
But senior Cabinet colleagues declared support for May, saying she must stay in office to steer the country through Brexit, due in 2019.
Environment Secretary Michael Gove, a prominent Brexit campaigner, said Friday that May had “shown tremendous grace and grit in the course of this week.”
“I think Theresa’s doing a great job,” he told Sky News.
Other Conservatives took to Twitter to back their leader. Lawmaker Nadhim Zahawi tweeted that he had been “inundated with message(s) of support” for May and Shapps had “misjudged the mood of the party.”
Legislator James Cleverley posted on Twitter that Shapps “is doing himself, the party, and (most importantly) the country no favors at all. Just stop.”