Theresa May has penned a public warning to MPs to back her twice-rejected Brexit deal with the European Union, or else “we will not leave the EU for many months, if ever.”

The Prime Minister’s proposed Brexit deal with the EU received the heaviest defeat of any Government in Britain’s recorded history in January, and was rejected again by slightly less crushing but still overwhelming 149 votes on March 12th.

By convention, parliamentary reverses of this scale — coupled with losing her party’s Commons majority in a 2017 snap election and being subject to a vote of no confidence in which a majority of Tory backbenchers said Mrs May should go — would have seen any other prime minister in modern times step down.

Mrs May is clinging doggedly to her office, however, planning a third parliamentary vote on her deal and a short delay to Brexit if it passes, or a very long delay to Brexit — or no Brexit at all — if MPs do not back it — despite repeated promises she would not do this and that the United Kingdom would be out of the EU with or without a deal come March 29th, as laid out in the European Union (Withdrawal) Act 2018.

“If Parliament can agree the deal before the European Council on March 21, we will seek a short technical extension to pass the necessary legislation… If it cannot, we will not leave the EU for many months, if ever,” she threatened bluntly in a March 17th article for The Sunday Telegraph.

WATCH | Here are all the times Theresa May told us we'd be leaving the EU on 29th March 2019. Today she has given our Remain Parliament the chance to block No Deal and extend Article 50. She has lied to the country for two years. Her betrayal will not be forgotten or forgiven! pic.twitter.com/b2detXDk1X — Leave.EU (@LeaveEUOfficial) February 26, 2019

Mrs May further warned that, while MPs rejected calls for a second referendum in the series of votes which authorised the Government to seek an extension of Article 50 — a move opposed by a majority of her own MPs and by the DUP which props up her minority government, but passed despite them with the help of anti-Brexit, left-liberal opposition parties — the “threat of a second referendum [does not] disappear entirely because Parliament has not voted for one now.”

Indeed, parliamentarians voted against a Scottish National Party (SNP) amendment to extend Article 50 and take No Deal off the table as recently as January 29th, and have now voted in favour of both those things, so the threat is far from idle.

Number 10 is clear on Article 50 – it will NOT be extended beyond 29 March next year. The PM's official spokesman said today: "The PM has been clear on a number of occasions she has no intention of extending Article 50. The Prime Minister is not going to extend Article 50." — Christopher Hope (@christopherhope) December 11, 2018

The Prime Minister’s entreaties carry little weight at this point, however, with the evident ease with which she has discarded her promises on No Deal being “better than a bad deal” and not extending Article 50 meaning she has permanently “lost the trust of eurosceptics”, according to her own senior aides.

If the Prime Minister was serious about delivering Brexit, as she claims, it would have been well within her power to deliver a clean break from the EU on March 29th, as mandated by the EU Withdrawal Act.

Any attempt by MPs — over 80 percent of whom derive their democratic mandate from manifestos which promised Brexit would be delivered — to sabotage this process could have been shut down by calling on the Queen to exercise her constitutional right to temporarily prorogue (suspend) the parliamentary session until after exit day.

The fact the Prime Minister has instead chosen to delay Brexit, threaten it might not happen at all, and allow MPs to vote against No Deal in any circumstances — essentially allowing the EU to veto Brexit, given they can simply decline to offer a deal on anything but unacceptable terms — has led many to suspect the former Remain campaigner does not really want it to take place.

Rees-Mogg: PM Must Call on Queen to Suspend Parliament to Stop Anti-Brexit MPs https://t.co/MfgpZksT5y — Breitbart London (@BreitbartLondon) January 25, 2019

Some Tory Brexiteers do appear to be wavering and considering giving their backing to the deal in the face of their Remainer colleagues blocking Brexit entirely, and indeed it is the Prime Minister’s contention that if it is rejected again, “EU leaders would require a clear purpose for any [delay]… If the proposal were to go back to square one and negotiate a new deal, that would mean a much longer extension – almost certainly requiring the United Kingdom to participate in the European Parliament elections in May.”

“The idea of the British people going to the polls to elect MEPs three years after voting to leave the EU hardly bears thinking about. There could be no more potent symbol of Parliament’s collective political failure,” she added.

However, other eurosceptics have noted that, despite Mrs May’s contention that backing her deal can “resolve this question now”, it does not actually settle the question of Britain’s future relationship with the EU.

Indeed, it merely buys the UK a so-called “transition” period for an estimated £39 billion — in which negotiations will continue, lasting possibly until the end of 2022 and during which Britain will effectively remain an EU member-state, minus EU representation; still subject to EU law, EU trade policy, EU migration rules, and EU court rulings.

Many Brexiteers fear that, if there is no actual, final deal by the end of the transition, Remainers will simply use the prospect of the contentious arrangements envisioned by the so-called “backstop” coming into force to argue it should not conclude with Brexit in practice as well as in name, but with a seamlessly switch back to formal membership — a fight Remainers will be much better prepared for at the end of 2022 than they are at present.

What’s the logic in voting for something that delivers a non-Brexit in order to avoid no Brexit? What’s the logic in voting for something that will put UK in a worse place (forever!) than remaining (where option to leave still exists)? The British public are not fools. — Richard Tice (@TiceRichard) March 17, 2019

Follow Jack Montgomery on Twitter: @JackBMontgomery