MPs are “not fooled” by the EU’s so-called assurances to Theresa May over the Irish backstop arrangement, Jeremy Corbyn said ahead of tomorrow’s crucial vote on the Brexit deal.

The Labour leader tore into the Prime Minister as he stated that “the government was in disarray,” reiterating that if “May’s deal is rejected, it is time for a general election, it is time for a new government.”

The PM is expected to have her plans for leaving the EU voted down tonight by a huge number of MPs.

At least 64 Tories have indicated so far that they intend to vote against it. Out of 639 MPs who will be able to take part in the vote, the number voting against the deal is currently projected to be around 383 — which includes almost all opposition MPs.

Ms May received a letter from European Council president Donald Tusk and European Commission president Jean-Claude Juncker today saying that they do not want the controversial backstop arrangement over the Irish border to be permanent.

But they stressed that they were “not in a position” to rewrite or amend the Withdrawal Agreement secured by Ms May last month.

Ms May said that their letter provided “valuable new clarifications and assurances” over the backstop, which is designed to prevent a hard border in Ireland.

Speaking in a factory in Leave-voting Stoke-on-Trent, she claimed that the letter proves the backstop was “not a threat or a trap.”

Later in the Commons, Mr Corbyn said it was clear to everyone that she had “completely and utterly” failed to get the legally binding assurances she promised last month as she pulled the MPs’ vote scheduled to have taken place then.

He said the assurances amounted to just “warm words and aspirations” as they “do not alter the fundamental meanings” of the agreement.

The blame of a failed Brexit “will lie firmly at the feet of government and the Prime Minister,” he stressed.

Mr Corbyn has pledged to table a motion of no confidence in the government in the hope of triggering a general election if the deal fails to get over the line.

The Democratic Unionist Party, which props up Ms May’s minority administration, dismissed the letter as “meaningless.”

DUP deputy leader Nigel Dodds, who called on the PM to demand changes to the agreement itself, said: “Rather than reassure us, the Tusk and Juncker letter bolsters our concerns.”

Tory MP Gareth Johnson quit the government as an assistant whip to oppose Ms May’s plan, saying it was clear there was “no significant change” to the widely unpopular agreement.

Labour MP Tulip Siddiq even postponed the date of her Caesarean section — planned so that she can give birth at 37 weeks due to gestational diabetes — so that she can vote against the deal.

The date of the delivery would have been today or tomorrow but doctors agreed to let her change the date to Thursday.

Usually, heavily pregnant MPs, those with babies and the sick are “paired” with an opposition MP who also cannot vote so the overall result is not affected.

But Ms Siddiq said her trust in the process broke down after the chief whip Julian Smith was accused of secretly telling Tory MPs to ignore the pairing arrangements before a Brexit vote last summer.