Senior Tory MPs could vote as early as next week on whether to change party rules to oust Theresa May, HuffPost UK has learned.

The prime minister was expected to resist calls from Sir Graham Brady, influential chairman of the 1922 committee of backbenchers, to set a date for her departure during Downing Street talks on Monday.

But there are likely to be demands among the 18-strong 1922 executive, who hold the key to May’s future, to hold another vote on changing party rules as soon as possible.

The PM is facing widespread anger over compromise Brexit talks with Labour and the lengthy delay to the UK’s departure from the EU to October 31.

But she is hanging on because she cannot be ousted by her own MPs until December under party rules, having survived a no confidence vote at Christmas.

The 1922 executive last month narrowly rejected changing the rules to allow a leadership challenge sooner, and they are unlikely to hold another vote when they meet on Wednesday to hear what May told Sir Graham.

But pressure is growing for another vote as soon as possible to “stem the tide” following the Tories’ drubbing in the local elections and potentially catastrophic European elections looming on May 23 – a little more than two weeks away.

According to the Evening Standard, two members who backed the PM last time – Cheryl Gillan and Sir Geoffrey Clifton Brown – are also considering changing their votes in what could be a decisive move.

One executive member told HuffPost UK: “If she steadfastly refuses to set out any sort of timescale, (the rule change) issue would be revisited.

“It doesn’t want to be left too long because the clock for the European elections is ticking.

“In my view, the process would be announced before the European elections because I think it’s a way of stemming the tide of what’s likely to happen in European elections.

“But if it isn’t then I would hope it would take place fairly soon after the European elections.”

Another executive member suggested the 1922 could “possibly” delay another vote on rule until after the European Parliament elections.

“But it is in flux,” they said. “Don’t make any assumptions at this stage.”

However Charles Walker, vice-chairman of the Tory 1922 Committee, suggested he would resist any rule change and blamed Tory rebels who refused to back the PM’s deal for the crisis.

“We are playing fast and loose as a party at the moment,” he told BBC Radio 4′s World at One.

“There are colleagues who have suggested the prime minister should go, the prime minister has said that she wants to leave early in her premiership, but she doesn’t want to leave this god almighty mess.

“I think there’s a blame displacement process going on within the Conservative party at the moment, laying it all on her shoulders. We all need to take personal responsibility for the fact that we are still in the EU and that we are in government.”

Another Tory MP said that colleagues should back whatever deal May strikes with Labour and then hold a summer recess leadership contest to run from late July until early September.

They told HuffPost UK: “We need a six week opportunity to talk to ourselves as a party rather than the country, which at the moment wants us to talk to the country in the national interest.

“So ideally we would get something resolved and then have a leadership election in summer, as the EU gets its new European Parliament together and there is less attention on Brexit.”

Even if May survives attempts by MPs to remove her for now, Conservative activists are expected to take the unprecedented step of voting on whether she should resign at an extraordinary meeting on June 15.

Andrew Sharpe, chairman of the National Conservative Convention, said the vote was triggered after more than 65 Tory association chairmen signed a petition.

They criticised the PM for seeking two Brexit delays, and added: “We no longer feel that Mrs May is the right person to continue as prime minister to lead us forward in the negotiations.

“We therefore with great reluctance ask that she considers her position and resigns, to allow the Conservative party to choose another leader, and the country to move forward and negotiate our exit from the EU.”

A Downing Street source indicated that May was unlikely to go before seeing through Brexit – a process which could in theory last months – unless MPs pass a withdrawal deal in the meantime.