Enough letters have been submitted by Conservative politicians to trigger a vote of no confidence in British prime minister Theresa May’s leadership, the BBC reported on Tuesday.

Citing multiple sources the broadcaster said MPs believe the tally of 48 letters has been reached.

It said the chairman of the Conservative 1922 committee, Graham Brady, has asked to see Mrs May on Wednesday after her weekly question session in parliament.

Andrew Bridgen, a long-standing critic of Mrs May, said he believed “Conservative MPs will vote whether they have confidence or not in a secret ballot at the first opportunity, which I think could be tomorrow night”.

Earlier Mrs May brushed aside speculation of an impending vote of no confidence in her leadership and said her is focus is on securing reassurances from EU leaders on her Brexit deal.

Mrs May spent the day in talks with fellow leaders including Germany’s Angela Merkel and Mark Rutte of the Netherlands. She said she had found a “shared determination” to address MPs’ concerns about the proposed backstop arrangement for the Irish border, in order to allow the deal to be brought back to the House of Commons and ratified.

The prime minister’s decision to delay a vote on the withdrawal agreement sparked a fresh wave of speculation at Westminster about new letters of no confidence being submitted to Sir Graham.

Some members of the European Research Group of Eurosceptic Tory MPs were earlier said to be claiming that enough letters had been submitted to trigger a vote.

Mrs May was asked whether she had been told the threshold of 48 letters had been reached.

“No, I have been here in Europe dealing with the issue I have promised parliament I would be dealing with,” she said.

What needs to happen for Mrs May to face a leadership contest?

A challenge is triggered if 15 per cent of the Conservative MPs write letters demanding a confidence vote to the chairman of the party’s ‘1922 Committee’, which represents those politicians who have no government jobs. The Conservatives have 315 MPs, so 48 would need to write such letters for a vote to be called.

Is this likely to happen?

In recent months, some eurosceptic MPs have publicly said they have submitted such letters in protest at Mrs May’s Brexit strategy. The number voicing concern rose after she delayed a planned vote on her Brexit deal in parliament when facing an almost certain defeat. However, the 1922 Committee’s chairman, Sir Graham Brady, is the only person who knows how many have actually submitted letters, including those who have written to him confidentially. He has not commented on the latest media reports that the threshold has been breached.

What happens if a vote is called?

All Conservative MPs can vote and Mrs May would need a simple majority of the total votes registered in order to win. If all elected MPs cast their ballots, that would currently mean 158 votes. If she wins, she remains in office and cannot be challenged again for 12 months. If she loses, she must resign and is barred from standing in the leadership election that follows.

How soon might a vote take place?

Under Conservative rules, the vote would be held as soon as possible, on a date decided by the 1922 Committee chairman in consultation with the party leader. The last no-confidence vote against a Conservative leader, when the party was in opposition in 2003, was held the day after the committee chairman announced he had received enough letters.

What happens if Mrs May loses?

There will be a leadership contest to decide her replacement. Her replacement will become prime minister, but a general election will not automatically be triggered. If several candidates come forward, a secret vote is held among Conservative MPs to whittle down the field. The candidate with the fewest votes is removed and Conservative politicians vote again. The process is repeated, on Tuesdays and Thursdays, until only two candidates remain. These two candidates are then put to a postal ballot of the wider Conservative Party membership. Participants need to have been party members for more than three months. When David Cameron decided to step down as prime minister and Conservative leader after the EU referendum in 2016, five candidates came forward. The field was narrowed to Mrs May and then-junior minister Andrea Leadsom, but she pulled out before members voted, leaving Mrs May to become leader unopposed.

Who could replace Mrs May?

The list of possible replacements is long with names such as Boris Johnson, Dominic Raab, Michael Gove, Sajid Javid, Jeremy Hunt and Amber Rudd all mentioned but there is no clear frontrunner. - Reuters/PA