Theresa May's woes deepened dramatically today as a Tory no-confidence vote was triggered.

Eurosceptics have secured the 48 letters from MPs needed to force a ballot that could end the PM's time as leader.

Sir Graham Brady, the chair of the powerful 1922 committee, said the threshold had been 'exceeded'.

'In accordance with the rules, a ballot will be held between 1800 and 2000 on Wednesday December 12.'

They believe former Cabinet minister Owen Paterson joining the efforts to oust Mrs May in the wake of her humiliating decision to drop a Commons vote on her Brexit deal has tipped the balance.

The chair of the powerful Conservative 1922 committee, Sir Graham Brady, is said to have requested a meeting with Mrs May after PMQs this lunchtime.

Only he knows whether the threshold has actually reached, and he never says how many letters he has received.

Mrs May's allies have repeatedly insisted she will fight any effort to oust her - but her position has weakened significantly over recent weeks and may now be under serious threat.

After the premier returned to Downing Street from a frantic tour of European capitals trying to save her Brexit deal last night, chief whip Julian Smith was seen going into No10.

Theresa May's woes deepened dramatically today amid signs she is on the verge of facing a Tory no-confidence vote. She is pictured in Berlin having met Chancellor Merkel

Theresa May met with Michel Barnier (pictured left) and Jean-Claude Juncker during a frenetic day of travel as she scrambles to try to win concessions that will buy off Tory rebels

Mrs May also held crucial talks with Angela Merkel in Berlin (pictured) earlier as she begs for help winning over furious MPs

Home Secretary Sajid Javid (left) is among the contenders to challenge Theresa May, while Jacob Rees-Mogg (right) has submitted a letter of no confidence

One senior Brexiteer told MailOnline Mr Paterson lining up with the rebels was a 'big moment' after the mutiny embarrassingly failed to gain traction before.

'We have had some false starts, but this looks like the green light,' they said.

Previously veteran Eurosceptics have appeared unwilling to sign up to an all-out revolt, despite deep unhappiness with Mrs May's Brexit plans.

The development risks throwing the government into turmoil just as Mrs May is scrambling to wring more concessions out of the EU.

She spent yesterday jetting between capitals, holding talks with Dutch PM Mark Rutte in The Hague, German Chancellor Angela Merkel in Berlin, and Donald Tusk and Jean-Claude Juncker in Brussels.

Theresa May to quit: What happens next? How does a leadership election work? The election to find Theresa May's replacement is held in two stages with up to 20 Tory MPs expected to try to stand. To join the battle, any candidate requires two other MPs to sign forms agreeing to be their proposer and a seconder. The race will start on June 7 and is expected last around six weeks with the new leader in place by the end of July. Mrs May is expected to remain as Prime Minister until a successor is appointed and ready to be confirmed by the Queen. How are candidates eliminated? Conservative MPs will hold a series of head-to-head ballots to whittle the list of contenders down to a final two, with the lowest placed candidate dropping out in each round. Who votes on the final two? There will then be a series of hustings involving the two final candidates - probably in all regions of the UK - and a TV debate could also be held. It is then the Tory members across the country step in. They will then have around a fortnight to vote via postal ballot - which Mrs May avoided after rival Andrea Leadsom dropped out of the race. The last time a postal vote was held was in 2005, when David Cameron grabbed the leadership. Advertisement

It is unclear whether she will stick to her plan to travel to Ireland for talks with Leo Varadkar tomorrow, and then go straight on to a crucial EU summit in the Belgian capital on Thursday and Friday.

One MP said tonight that pressing ahead with the trips would have worrying echoes of Margaret Thatcher leaving the UK as she faced a leadership challenge in 1990.

Mrs May can stay on if she wins the confidence ballot by just one vote - and would theoretically be immune from challenge for another 12 months.

But in reality anything short of a handsome victory will make it almost impossible for her to cling on.

In his letter to Sir Graham, published in The Daily Telegraph, Mr Paterson said the Prime Minister had failed to prepare for a no-deal Brexit, tried to bounce her ministers into supporting her and approached negotiations like a 'feeble and unworthy' supplicant.

'These mistakes have eroded trust in the Government, to the point where I and many others can no longer take the Prime Minister at her word,' he wrote.

'She has repeatedly said 'no deal is better than a bad deal', but it is clear her objective was to secure a deal at any cost.

'The conclusion is now inescapable that the Prime Minister is the blockage to the wide-ranging free trade agreement offered by (European Council president Donald) Tusk which would be in the best interests of the country and command the support of Parliament.'

It comes just hours after a former minister warned Brexit is 'certain to fail' while she remains party leader.

Steve Baker urged colleagues to be 'brave' and send letters to the powerful Conservative 1922 committee that would start the process of evicting the PM.

He also insisted Mrs May should consider her own position after being forced to postpone a crunch Commons Brexit vote to avoid humiliating defeat.

The brutal attack from the former Brexit minister came as the tally of MPs confirmed as having sent no-confidence letters to 1922 chair Sir Graham Brady hit 28, with Crispin Blunt adding himself to the list.

There is said to have been a surge in numbers during the day, with Mr Paterson's decision apparently swaying wavering MPs.

When the figure reaches 48 a formal no-confidence vote of Tory MPs is triggered, in which Mrs May would need to gain majority support to survive.

The Conservative process is separate from a no-confidence vote in Parliament, where MPs of all political stripes take part.

George Freeman, a former Downing Street policy chief, desperately urged MPs today not to send letters to Sir Graham, warning of the damage to party and country.

The former Tory minister pleaded: 'To any colleagues thinking of signing their letter to Mr Brady to trigger a leadership election, I beg you not to. The country would never forgive us.'

A leadership contest would throw Brexit as well as the Tories into turmoil. Mrs May decided earlier this week not to put her deal to a vote, accepting it would be heavily defeated.

She announced she would try to secure fresh concessions on the Irish border backstop, and would hold a fresh parliamentary vote by January 21. A challenge would throw that calendar into chaos.

The Prime Minister had breakfast in the Netherlands with counterpart Mark Rutte this morning before going on for her other engagements

Steve Baker urged colleagues to be 'brave' and send letters to the powerful Conservative 1922 committee that would start the process of evicting the PM

Jacob Rees-Mogg, chair of the European Research Group (ERG) bloc of Tory Eurosceptics (pictured today in Westminster) has been urging MPs to replace Mrs May for weeks

Rivals have been brazenly jostling for position to succeed her in the Tory top job.

Secretary Sajid Javid fuelled speculation he could seek to replace Mrs May by giving an extraordinary interview last night setting out his vision for the country.

Boris Johnson also thrust himself into the spotlight by talking about his weight loss.

Any contest would be held as soon as possible. However, with Mrs May due to be out of the country on Thursday and Friday, it might have to wait until Monday.

A Tory former minister said: 'Things have really shifted in the past week and I think she would lose that vote now.

'I and others have been holding back from writing letters because of fears she would win a confidence vote, but the mood is shifting among MPs and our members.'

However, Mrs May's critics remain divided on who should replace her if they succeed, with Dominic Raab and Esther McVey also often cited as candidates by Brexiteers.

Mr Baker and Jacob Rees-Mogg, chair of the European Research Group (ERG) bloc of Tory Eurosceptics, have been urging MPs to replace Mrs May for weeks.

But despite a big push last month they embarrassingly failed to achieve the required level of support for a challenge.

Mr Rees-Mogg said yesterday that Mrs May must 'govern or quit'.

And Mr Baker told BBC Radio 4's Today programme: 'Of course, we have all taken a bit of a bruising on this and it is a grave decision for every colleague to make.

'But what I would say to my colleagues is: you now face the certainty of failure with Theresa May, you must be brave and make the right decision to change prime minister, and change prime minister now.'

Mrs May is on a frantic a last-ditch mission to salvage her Brexit deal today as the Tory civil war rages at home.

She is meeting Dutch counterpart Mark Rutte for breakfast in the Hague, before heading for crucial talks with Angela Merkel in Berlin.

Mrs May, pictured with Dutch PM Mark Rutte today, is on a frantic a last-ditch mission to salvage her Brexit deal today as the Tory civil war rages at home

Who has sent letters of no confidence in May? Letters of no confidence in Theresa May are confidential - but some of her strongest critics have gone public. If 48 letters are sent a vote is called. This is who has definitely sent a letter: Jacob Rees-Mogg , North East Somerset, Jacob.reesmogg.mp@parliament.uk Steve Baker , Wycombe, steve.baker.mp@parliament.uk Sheryll Murray , South East Cornwall, sheryll.murray.mp@parliament.uk Anne-Marie Morris , Newton Abbott, annemarie.morris.mp@parliament.uk Lee Rowley , North East Derbyshire, lee.rowley.mp@parliament.uk Henry Smith , Crawley, henry.smith.mp@parliament.uk Simon Clarke , Middlesbrough South and East Cleveland, simon.clarke.mp@parliament.uk Peter Bone , Wellingborough, bonep@parliament.uk James Duddridge , Rochford and Southend East, james@jamesduddridge.com Philip Davies , Shipley, daviesp@parliament.uk Andrea Jenkyns , Morley and Outwood, andrea.jenkyns.mp@parliament.uk Andrew Bridgen , North West Leicestershire, andrew.bridgen.mp@parliament.uk Nadine Dorries , Mid Bedfordshire, dorriesn@parliament.uk Laurence Robertson , Tewkesbury, robertsonl@parliament.uk Martin Vickers , Cleethorpes, martin.vickers.mp@parliament.uk Ben Bradley , Mansfield, ben.bradley.mp@parliament.uk Adam Holloway , Gravesham, hollowaya@parliament.uk John Whittingdale , Maldon, john.whittingdale.mp@parliament.uk Maria Caulfield , Lewes, maria.caulfield.mp@parliament.uk Mark Francois , Rayleigh and Wickford, mark.francois.mp@parliament.uk David Jones , Clwyd West, david.jones@parliament.uk Marcus Fysh , Yeovil, marcus.fysh.mp@parliament.uk Chris Green , Bolton West, chris.green.mp@parliament.uk Zac Goldsmith , Richmond Park, zac@zacgoldsmith.com Bill Cash , Stone, cashw@parliament.uk Philip Hollobone , Kettering, philip.hollobone.mp@parliament.uk Andrew Lewer, Northampton South, andrew.lewer.mp@parliament.uk Crispin Blunt , Reigate, crispinbluntmp@parliament.uk Owen Paterson , Shropshire Patersono@parliament.uk Advertisement