It is the Monday after “Super Saturday” – when the Commons held a weekend sitting for the first time in 37 years – but it did not go as Prime Minister Boris Johnson had hoped. So what now?

– What happened on Saturday?

Mr Johnson hoped it would be the day that Parliament would back his deal, but it was not to be. His Brexit deal dream was scuppered – for now – by the much-talked-about Letwin amendment.

MPs voted by a majority of 16 to back the amendment put forward by former Cabinet minister Sir Oliver Letwin to withhold approval of the Brexit deal agreed between Mr Johnson and Brussels “unless and until implementing legislation is passed”.

Sir Oliver, who lost the Tory whip for voting against the Government on Brexit previously, said the amendment was “insurance” against the UK crashing out of the EU without a deal by mistake on the scheduled deadline of October 31.

Sir Oliver Letwin after it was announced that the amendment, which seeks to avoid a no-deal Brexit on October 31, had been backed (Stefan Rousseau/PA)

– How did the Government react?

The Prime Minister decided not to have a so-called “meaningful vote” on his deal in light of the Letwin amendment passing.

The Government introduced the Withdrawal Agreement Bill (WAB) in the Commons on Monday, with a second reading vote likely to take place on Tuesday.

– What is the WAB?

The WAB is the Government’s Brexit bill – the legislation needed for Brexit – which would implement the new deal agreed with the EU in UK law.

Brexit Secretary Stephen Barclay said: “If Parliament wants to respect the referendum, it must back the bill.”

– But will there be another vote on the deal, and if so when?

Jacob Rees-Mogg, the Leader of the House of Commons, said at the weekend that the Government wanted to hold another meaningful vote on Mr Johnson’s deal on Monday.

Commons Speaker John Bercow, who Tory Brexiteers have accused of being pro-Remain, ruled on Monday afternoon that the Government could not bring the so-called “meaningful vote” on its plans.

As many expected, he said the Government’s motion on Monday was the same in substance as the one considered on Saturday by MPs.

– Could Mr Johnson still get his deal through Parliament?

Yes, but time is running out before the October 31 deadline as the European Parliament would also need to ratify it, and it is unclear how soon MEPs will do that.

The European Parliament’s chief Brexit official, Guy Verhofstadt, said last week MEPs will only start their work once the UK Parliament has passed a fully-binding Brexit deal, and on Monday evening he said the Brexit Steering Group had met to discuss the latest developments in the UK.

He tweeted: “We agreed to advise the Conference of Presidents to await the full ratification on the UK side before the @europarl votes on the deal. It’s now up to the UK Parliament to make their choice.”

And without a meaningful vote in Parliament, support for the agreement has not yet been tested.

Though the PM has attracted support from a number of prominent Brexiteer Tories, including the European Research Group (ERG), the DUP is strongly opposed to the deal.

– What will happen now that John Bercow has blocked a vote on the deal on Monday?

Focus will switch to the Government bringing its WAB before MPs, with a vote on its second reading on Tuesday.

Ministers insist they “have the numbers” to push the agreement through, but the parliamentary situation appears to be on a tightrope.

Labour has made clear it will try to hijack the legislation by putting down amendments for a second Brexit referendum and a customs union with the EU.

– What about the letters sent to the EU by Mr Johnson?

An unsigned letter sent by Prime Minister Boris Johnson to the European Council president Donald Tusk (Downing Street/PA)

Under the terms of the Benn Act, which was passed against the PM’s wishes, the Prime Minister was compelled to write to the EU asking for a three-month Brexit extension if he had not secured a deal by 11pm UK time on October 19.

He told the Commons: “I will not negotiate a delay with the EU, and neither does the law compel me to do so.”

But the Prime Minister did send two letters to European Council president Donald Tusk.

First, there was an unsigned photocopy of the request he was obliged to send under the Benn Act, followed by a letter explaining why the Government did not actually want an extension.

– So will the EU grant an extension?

Despite European Commission president Jean-Claude Juncker raising doubts over another Brexit delay, the decision needs to be taken by all 27 remaining EU states, not him.

On Saturday night, Mr Tusk said he would now start “consulting EU leaders on how to react”.

The EU could set a different length to an extension, either shorter or longer than the three-month one cited in the Benn Act.

The EU may also decide not to formally respond to such a letter from the PM until it sees if Mr Johnson can get the Withdrawal Agreement Bill through Parliament.

Despite all this, the PM is insisting that the UK will still quit the EU in 10 days.

– Will there be an emergency EU summit?

If the PM gets the Withdrawal Agreement Bill through, there could be a special gathering of leaders on October 28.

If the deal needs more time at that stage to get through Parliament, leaders could agree to a short extension.