Britain was on general election alert last night after Whitehall chiefs were ordered to draw up contingency plans for a snap poll.

Amid the fragile situation in Westminster, Britain’s top civil servant told Government departmental heads to be ready in case an election is needed to break the Brexit deadlock.

Cabinet Secretary Sir Mark Sedwill met senior mandarins this week to discuss preparations in case Theresa May decides to go to the country.

Today, it also emerged that official guidance has now been drawn up on the possible timeline for a second Brexit referendum.

A document, apparently presented at cross-party Brexit talks, suggested that another referendum would take 15 months to arrange and hold.

Downing Street has repeatedly insisted the next general election will not take place until 2022, as mandated by the Fixed Terms Parliament Act.

Theresa May makes a statement following winning a confidence vote, after Parliament rejected her Brexit deal, outside 10 Downing Street yesterday

Only this week, the Prime Minister told MPs that holding a ballot now would be ‘the worst thing we could do’, with some Tories fearing that the party would lose seats to Labour, handing the keys to Number 10 to Jeremy Corbyn.

But Cabinet ministers have held conversations about how an election may now be the only way to move forward, with one warning a poll is ‘on the way’.

Despite the failure of its attempt to oust the Government this week, Labour has also not ruled out the possibility of repeatedly tabling no-confidence motions in a bid to topple Mrs May.

But an election might receive a weary reaction from voters. When Mrs May called the 2017 snap election, the news elicited the immortal response from one voter, Brenda from Bristol: ‘You’re joking! Not another one!’

As the aftershocks of the Brexit deal defeat continued:

÷Labour leader Mr Corbyn faced a fresh backlash as he ordered Labour MPs to snub cross-party talks to break the impasse;

Cabinet Secretary Sir Mark Sedwill met senior mandarins this week to discuss preparations in case Theresa May called a general election

÷Chancellor Philip Hammond came under fire from Eurosceptic Tory MPs after saying that the ‘threat’ of leaving without a deal could be taken ‘off the table’;

÷A Tory MP claimed the Prime Minister faces a mass walk-out of ministers unless she agrees to give Parliament control over Brexit;

÷It was announced that Mrs May will publish a new Brexit plan on Monday with a full debate and key vote scheduled for January 29.

÷German business chiefs have warned that a no-deal Brexit would be catastrophic for their country.

Civil servants across Whitehall have been ordered to prepare for the possibility that an election could be called.

The Daily Mail has learnt that officials have begun exercises looking at what needs to happen if there is a vote, such as rushing through final pieces of legislation before Parliament is dissolved.

Some Tories fear that the party would lose seats to Labour is another General Election was called, handing the keys to Number 10 to Jeremy Corbyn

Sir Mark, who was appointed Cabinet Secretary in October, held a meeting with permanent secretaries from across Whitehall this week to talk about how they needed to be ready in the event of all scenarios.

And on Wednesday Former Tory party leader William Hague told City of London figures that he believed the Brexit crisis may lead to a snap general election.

Labour has launched a fundraising drive to prepare for the possibility of a poll and in an email to supporters this week said the party was ‘on a snap election footing’.

And the Tories have begun selecting candidates in dozens of seats, although sources insisted this was part of the normal process.

An election could be triggered if rebel Tory MPs and the Democratic Unionist Party choose the nuclear option and – in alliance with opposition parties – collapse the Government by voting it down under the Fixed Term Parliaments Act.

Alternatively, the Prime Minister could decide there is no way forward on Brexit with the current parliamentary arithmetic and ask MPs to bring about a fresh vote.

If an election is called, it is likely that the two-year Article 50 process for leaving the EU would have to be extended beyond March 29.

Civil servants across Whitehall have been ordered to prepare for the possibility that an election could be called

Last night, a Cabinet Office spokesman said: ‘The Cabinet Secretary frequently meets with permanent secretaries to discuss a wide range of issues.’

Today Mrs May – who has repeatedly ruled out ever staging a second referendum – shared civil service advice on the issue during talks with opposition MPs.

The revelation is the first acknowledgement that Government officials have carried out work on how a second vote might be held.

But the projected timetable, which suggests it would take 15 months to arrange and hold a second referendum, sparked anger amongst some campaigners.

Downing Street confirmed that officials had prepared a ‘short paper’ on how a second referendum might work, in anticipation of it being raised by opposition MPs.

A spokesman for the PM insisted the document did not suggest Mrs May was planning for – or even considering – a second referendum.

Corbyn faced a fresh backlash as he ordered Labour MPs to snub cross-party talks with Mrs May to break the impasse

One source said the one-sheet paper had taken officials ‘no more than a couple of hours’ to produce.

The document set out the potential timetable for a second referendum, including seven months to pass the necessary legislation, 12 weeks for the Electoral Commission to test the question and 16 weeks for the campaign.

Mrs May faces a mass walk-out of ministers unless she agrees to give Parliament control over Brexit, an MP has claimed.

Nick Boles said up to 20 middle-ranking and junior ministers are ready to resign if the Prime Minister tells them to oppose an amendment empowering the Commons to drive the agenda.

By TIM SCULTHORPE, DEPUTY POLITICAL EDITOR FOR MAILONLINE

William Hague (file) has predicted chaos over Brexit could force a general election within weeks amid a stalemate in Parliament

William Hague has predicted chaos over Brexit could force a general election within weeks amid a stalemate in Parliament.

The former Tory leader made the claim in a briefing for businessmen in the City of London in the aftermath of the crushing defeat for Theresa May's Brexit plans.

Lord Hague correctly predicted the last snap election in 2017 and warned the chances of another are currently being 'underplayed'.

Calling a snap election is one idea being considered by some Cabinet ministers in the aftermath of the record-breaking 432 to 202 defeat on Tuesday night.

In a briefing with Citigroup clients yesterday, Lord Hague said 'the media are underplaying the chances of a general election in the coming weeks', one person at the meeting told the Financial Times.

A minister told the paper: 'William is right: chaos will eventually lead to a general election.'

Calling an election would mean giving into demands from Labour leader Jeremy Corbyn there needs to be another vote.

Mrs May would need to get the support of two thirds of MPs to call an election again - the same process she used in April 2017.

Many in Westminster think a snap election would produce a similarly ambiguous response as last time, when Mrs May lost the Tory majority.

The PM herself warned MPs yesterday there was a risk no party would get a majority and an election would do nothing more than deepen the chaos facing the country.

Mrs May has spent today meeting Opposition MPs to try and find a way forward after Tuesday's humiliation.

The PM and her Cabinet have been holding a frantic round of cross-party meetings after she held out an olive branch following a failed Labour bid to oust her.

Calling an election would mean giving into demands from Labour leader Jeremy Corbyn (pictured today in Hastings) there needs to be another vote

Tory Eurosceptics including David Davis, DUP leader Arlene Foster, and Green MP Caroline Lucas were among the key players spotted out and about in Whitehall today as efforts to forge consensus are ramped up.

However, Jeremy Corbyn and Nicola Sturgeon have caused fury by flatly rejecting the overture, insisting they will not talk until the government rules out leaving the EU without a deal. Mrs May has said the option must stay on the table, and dismissed calls to delay the exit date from March.

But it has emerged she could face a major uprising within government over a bid by Tory MP Nick Boles to prevent a no-deal Brexit.

Mr Boles is tabling an amendment that would empower backbenchers to push through legislation extending the Article 50 process by nine months - effectively avoiding a cliff edge.

He told the Evening Standard that around 20 ministers are ready to resign if Chief Whip Julian Smith tries to order them to oppose the amendment, which would be considered alongside Mrs May's 'Plan B' on January 29.

A number of Cabinet members are also said to have vowed that they will not oppose the mechanism. Chancellor Philip Hammond suggested he supported the idea in a conference call with business leaders this week.