Theresa May scrambled to defuse a bitter row with Brexiteers today after her EU envoy was overheard saying she will put off a vote on her deal until the last moment - and then threaten to delay the UK's departure unless they approve it.

Olly Robbins loudly told companions in a hotel bar that the 'week beginning end of March' would be critical, just days before the UK is due to leave the bloc.

He suggested MPs will be confronted with a 'long extension' to the Article 50 process if they do not give the plan the green light at that point.

The private conversation, which happened within earshot of an ITV journalist on Monday night, sent Brexiteers into meltdown.

Mrs May has repeatedly insisted that the UK will leave on schedule on March 29 - despite growing doubts among ministers over whether that is realistic even if her package was passed immediately.

She was grilled about the issue at PMQs this afternoon, with Tory Henry Smith asking her to reject the 'chatter'. Mrs May said the claims were based on what 'someone said to someone else, as overheard by someone else, in a bar'.

However, she risked inflaming the situation by stopping short of ruling out a delay to the Brexit date,

'This House voted to trigger Article 50,' she told MPs. 'That had a two-year timeline. That ends on the 29th March.

'We want to leave with a deal and that is what we are working for.'

Chief negotiator Olly Robbins was overheard talking in a bar about Mrs May and Brexit

After the comments by Mr Robbins emerged, Tory hardliners accused the PM of 'ignoring the wishes of the British people'.

Former Ukip leader Nigel Farage branded the senior civil servant part of a 'fifth colum' and said he should be sacked.

The bitter row erupted as Mrs May braces for the latest round of crunch Brexit votes in the Commons tomorrow.

There is anger that the government has tabled a motion endorsing the 'approach to leaving the EU expressed by this House' in a previous showdown on January 29. Those votes saw MPs pass a non-binding motion stating their opposition to leaving the bloc without a deal.

Remainers have made clear they will hold off an all-out rebellion to rule out no deal at this stage - but ministers are threatening to join a revolt in two weeks' time if she has not made a breakthrough in talks with the EU by then.

Who is Brexit envoy Oliver Robbins? Known as the mandarin's mandarin, Olly Robbins has been the PM's indispensable Europe adviser since she took personal charge of the negotiations over Britain's departure from the EU. Reputed to be the only person in Whitehall to grasp fully the complexities of the British negotiating position, Mr Robbins heads the Cabinet Office Europe Unit. However, the civil servant is widely distrusted by Brexiteers, who have accused him of trying to engineer the softest possible break with the EU. And while his mastery of the detail may be unrivalled, some have also questioned whether he has the required experience negotiating in the corridors and backrooms of Brussels. Mr Robbins originally worked under former Brexit Secretary David Davis in the Department for Exiting the EU, but moved to Downing Street in September 2017. Some in the Leave camp believe he was the true architect of the doomed Chequers plan, drawn up in the Cabinet Office while Mr Davis and other Brexit ministers were kept in the dark. Prior to his Brexit role Mr Robbins had a long Civil Service career, working under every prime minister since Tony Blair, when he served as the Labour leader's principal private secretary. Aged 43, the Oxford graduate has held senior roles in the Treasury and Home Office and was also deputy national security adviser under David Cameron. Advertisement

Mr Robbins was overheard by ITV's Angus Walker following the meeting at the UK Ambassador's Residence between Michel Barnier and Brexit Secretary Stephen Barclay.

'The issue is whether Brussels is clear on the terms of extension,' he was overheard saying by Mr Walker.

'In the end they will probably just give us an extension.'

Asked whether the comments reflected Government policy, Mr Barclay said this morning: 'No.'

Mr Barclay told BBC Radio 4's Today: 'The Prime Minister has been very clear that we are committed to leaving on March 29.'

The Cabinet minister also tried to defuse Eurosceptic anger that the PM's motion effectively rules out no deal by endorsing the results of the votes held last month.

Mr Barclay said that contingency planning for no deal was 'the agreed position of the Cabinet'.

'The agreed policy of Cabinet is to secure a deal. That's our priority and that's what we are working on.'

Mr Robbins, the UK's chief Brexit negotiator, had been at the 'constructive' talks between Mr Barclay and Mr Barnier on Monday night before heading for the hotel bar.

Angus Walker wrote for ITV: 'Robbins said that, in his view, he expects the choice for MPs to be either backing May's deal or extending talks with the EU.

'He expects MPs in March to be presented with backing a reworked Brexit deal or a potentially significant delay to Brexit...

'Robbins added that he thought the fear of a long extension to Article 50 might focus MPs' minds.'

Theresa May has always denied she wants to remain in a permanent customs union with the EU - which is a key demand of Labour.

But comments made by Mr Robbins suggest that may have been the original plan.

The envoy apparently confirmed that the Irish backstop was designed not as a 'safety net' to avoid a hard border but as a 'bridge' to the long-term trading relationship.

Mr Robbins was quoted saying: 'The big clash all along is the 'safety net. We agreed a bridge but it came out as a 'safety net'.'

A furious row has erupted after Theresa May (pictured at PMQs today) tabled a motion for crunch Commons votes tomorrow seemingly accepting the UK must not crash out of the EU

It was also suggested Mr Robbins and the Prime Minister will seek to have the Withdrawal Agreement amended so that the Good Friday Agreement would be less of an obstacle' on the backstop

To do that they will attempt to have the European Commission 'agree that the word 'necessary' in the Northern Ireland protocol is defined as 'necessary subject to the future trade deal'.'

Tory Brexiteer Andrea Jenkyns tweeted: 'If true, the PM should stop ignoring the wishes of the British people and disregarding her own red lines.'

Former Ukip leader Nigel Farage said Mr Robbins was part of the 'Civil Service fifth column' and called for him to be sacked for his combination of 'treachery and incompetence'.

Tory Eurosceptics accuse May of ruling out no-deal Brexit Theresa May is on a collision course with Brexiteers today after they accused her of a 'sneaky' bid to rule out leaving the EU without a deal. A furious row has erupted after the PM tabled a motion for crunch Commons votes tomorrow seemingly accepting that the UK must not crash out of the bloc. The spat centres on a Remainer-backed amendment that was passed by MPs two weeks ago rejecting the idea of no deal. Although that vote was not binding on ministers, the government motion due to be considered tomorrow endorses 'the approach to leaving the EU expressed by this House on 29 January'. That has been interpreted by Brexiteers as Mrs May admitting that no deal is off the agenda - despite her repeatedly insisting it is a possibility. The bitter row risks condemning the PM to a humiliating defeat in Parliament, as the Tory Eurosceptic ERG group refuses to join her in the division lobbies. Advertisement

Steve Baker, the deputy chairman of the pro-Brexit Tory European Research Group, urged the PM to ignore Mr Robbins.

'Officials advise. Ministers decide. If the PM decides we are leaving on March 29, deal or no deal, that will happen,' he said.

Mrs May is running short on time.

More than a dozen ministers could join the revolt at the showdown on February 27 as pro-EU MPs told MailOnline the votes will finally be the crunch moment for no deal.

Earlier, the PM urged MPs to 'hold their nerve' as she appealed for 'a little more time' to get concessions on the Irish border backstop in bitter Commons clashes.

However, EU chief negotiator Mr Barnier emerged from the dinner with Brexit Secretary Steve Barclay in Brussels last night to insist the Withdrawal Agreement will not be renegotiated.

The Tory leader tried to quell a mounting rebellion by Remainers by promising them another chance to influence the Brexit process by the end of the month if her renegotiation is not complete.

But Mrs May fuelled anger that she is playing for time to reach March 29 by refusing to give a firm date by which a final vote on her deal will be held.

She reportedly told the cabinet it is 'clear' more time is needed.

Mrs May said: 'The talks are at a crucial stage. We now all need to hold our nerve to get the changes this House has required and deliver Brexit on time.

'By getting the changes we need to the backstop; by protecting and enhancing workers' rights and environmental protections; and by enhancing the role of Parliament in the next phase of negotiations I believe we can reach a deal that this House can support.'

In a rebuke to Jeremy Corbyn, Mrs May dismissed his call for a permanent customs union with the EU, saying the idea was 'less desirable' than her existing deal and the House had already voted against it in principle.

Earlier this week she stopped short of ruling out a customs union in a letter to Mr Corbyn which caused angry ripples among the more hardlines Conservatives.

Labour leader Jeremy Corbyn faced off with Mrs May over Brexit at the PMQs session today

With 45 days to go, former attorney general Dominic Grieve warned that time was running perilously short for ratification of any deal under the terms of the Constitutional Reform and Governance Act.

The Act, passed by the coalition government in 2010, requires 21 sitting days before the ratification of any international treaty.

But Mrs May made clear the government would get rid of the requirement if necessary.

'In most circumstances, that period may be important in order for this House to have an opportunity to study that agreement,' she said.

'But of course, in this instance MPs will already have debated and approved the agreement as part of the meaningful vote.

'So while we will follow normal procedure if we can, where there is insufficient time remaining following a successful meaningful vote, we will make provision in the Withdrawal Agreement Bill - with Parliament's consent - to ensure that we are able to ratify on time to guarantee our exit in an orderly way.'

A spokesman later explained that the process would be accelerated by a clause in the Withdrawal Agreement Bill itself, which would disapply the terms of the 2010 Act in this case.

Mrs May sidestepped demands from several MPs to spell out whether she would ask the EU for an extension to the two-year Brexit negotiation process or allow the UK to crash out without a deal if she hit the March 29 deadline with no agreement.

Earlier, Mrs May gave the Cabinet details of what had happened on her visit to Brussels last week, spelling out that she had suggested replacing the backstop with 'alternative arrangements', or inserting a time-limit or a 'unilateral exit mechanism'.

What will happen next in the unfolding Brexit drama? Valentine's Day MPs will hold another round of votes on Brexit. They are not due to pass judgement on Theresa May's deal - instead debating a 'neutral' motion simply saying that they have considered the issue. However, a range of amendments are set to be tabled. They could include proposals to delay the Brexit date beyond March 29. Labour is pushing a change that would force another 'meaningful vote' on the PM's Brexit deal by February 26, regardless of whether she has finished renegotiating the package with the EU. February 24-25 Mrs May could have an opportunity to seal a new package with fellow EU leaders at a joint summit with the Arab League in Sharm el-Sheikh. However, it is not clear how many will attend the gathering - or whether she will have completed the deal by then. February 27 Downing Street is trying to head off a potential Tory Remainer mutiny by promising MPs will get another set of votes by this date regardless of whether there is a final deal. March 21-22 The PM will attend a scheduled EU summit in Brussels that would effectively be the last opportunity to get agreement. Some MPs fear that Mrs May is trying to delay for as long as possible, and might even try to hold a make-or-break vote in the Commons on March 26. That would be just 72 hours before Brexit, giving them a very stark deal-or-no-deal choice. 11pm, March 29 The UK is due to leave the EU with or without a deal, unless the Article 50 process is extended with approval from the bloc's leaders, or revoked to cancel Brexit altogether. Advertisement