• Conservative rebels are closing in on a leadership challenge against Theresa May.
  • Reports suggest party officials have almost reached the 48-letter threshold required for a vote of no confidence in the prime minister.
  • Those mounting the challenge tell Business Insider they are confident the threshold will be breached within days.
  • However, the failure to reach the threshold so far has led some Conservative MPs to believe the challenge could fizzle out.

LONDON – Theresa May could face a leadership challenge within the next 24 hours as reports suggest that rebel Conservative MPs are just a handful of letters away from triggering a vote of no confidence in her.

May returns to Westminster on Monday with one report suggesting that party authorities have received 42 of the 48 required letters of no confidence in her leadership.

The European Research Group of pro-Brexit Conservative MPs, who are leading the challenge against May, believed the figure had already reached 48 letters on Friday.

Steve Baker, a leading member of the group, told colleagues in a Whatsapp group: “My count is over 48 with about a dozen probables on top.” However, Baker later rowed back on that prediction, and this morning The Sun reports that the number is 42, meaning six Conservative MPs need to submit letters to trigger a no-confidence motion.

"If everyone does what they've told me, the line will be crossed by a big margin on Monday evening," Baker said.

"However, it has become very very clear that not everyone does what they've said they're going to do. Conservative members of parliament who have decided that the only way to change the policy is to change the leader must have the courage and integrity to write the letter themselves. Simply telling me they're going to obviously isn't good enough."

One source in the ERG told Business Insider on Friday that they were "smirkingly confident" that they would reach the required 48 figure withing day but added that they were in "no rush" to reach it.

They said the key moment of danger would come on Monday evening when May faces a possible Commons defeat on the government's Finance Bill.

A cross-party amendment attempting to force the government to publish their economic assesment of the impact of a no-deal Brexit has been signed by over 70 MPs, including 11 Conservatives. If the DUP were to join the rebellion it could trigger a decisive blow against the prime minister and trigger a final wave of letters, the rebels believe.

However, the ERG is not unanimous in wanting a challenge. Baker, group leader Jacob Rees-Mogg, and numerous other members have publicly revealed their no-confidence letters. However, other members have told Business Insider that they are reluctant to challenge May at such a crucial point in the Brexit process.

"I have not submitted a letter and am very unlikely to do so before March 30th, 2019," one told BI.

Conservative MPs who dislike May's Brexit deal returned to their constituencies over the weekend to deliberate over whether to submit letters. If 48 letters are not reached today, the chances of a no-confidence vote could diminish.

"The fact that there hasn't been an announcement of 48 letters in already is very telling," one Conservative MP told BI.

Theresa May

Foto: sourceWPA Pool/Getty Images

The prime minister will spend this week selling her Brexit deal to MPs, businesses and members of the public.

This morning she will address the Confederation of British Industry's annual conference, where she is expected to say that her deal "fulfils the wishes of the British people as expressed in the 2016 referendum."

Carolyn Fairbairn, the CBI's director-general, declared support for May's deal on Sunday, telling Sky that while it "was not perfect" it provided stability to businesses and represented a path to a future free trade deal.

In Westminster, pro-Brexit Cabinet members want to alter May's Brexit deal. Andrea Leadsom, Michael Gove, Penny Mordant, Liam Fox and Chris Grayling want the political declaration on the future relationship to include sufficient detail on the future trade deal and the conditions in which the UK can leave the controversial backstop.

"There are things, particularly in the political decleration, which could give certainty to how we leave the backstop... Things like that are worth staying on for," an ally of Leadsom told BI.

The aforementioned Cabinet ministers have played down reports of a secret plot to change the Brexit deal. Fox has defended May in an opinion piece for The Telegraph. Last week the pro-Brexit trade secretary warned rebel Conservatives: "We aren't elected to do what we want. We are elected to do what's in the national interest."

The decision of the five ministers to stay in Cabinet rather than resign like Dominic Raab and Esther McVey did on Thursday was a boost for the prime minister. However, an ally of Leadsom did not rule out the former Conservative leadership candidate quitting at a later date.