Theresa May will make the closing speech in the resumed debate on her Brexit Plan in a last-ditch attempt to rally MPs behind it before they vote next Tuesday evening, Downing St has announced.

However, a key bone of contention is likely to be at what point MPs hear of the fresh concession expected from Brussels.

The Prime Minister’s spokesman indicated that any new assurances would come before the vote, rather than before the start of the debate, which takes place tomorrow and which will be opened by Stephen Barclay, the Brexit Secretary.

Asked if MPs would have a period of time to debate Brussels’ expected new offer, he replied: “I would anticipate that would be the case, yes.”

Read more: 200 MPs call on Theresa May to rule out no-deal Brexit as she seek fresh guarantees from Brussels

However, politicians from all sides are likely to be very unhappy at the prospect of resuming their debate for four days only to learn about any new concession on the final day of debate and just hours before the vote.

Earlier, Leo Varadkar, the Irish Prime Minister, said the EU was "happy to give" the UK fresh assurances over the Northern Irish backstop, declaring: "We don't want to trap the UK into anything."

Speaking to the Irish Times, the Taoiseach said there was currently "close contact between the UK and EU institutions on whether a further set of written guarantees, explanations and assurances could make a difference".

He went on: "Bear in mind, a lot of the opposition to the Withdrawal Agreement and the backstop might be based on suppositions and misunderstandings about our intent as a European Union.

"We don't want to trap the UK into anything; we want to get on to the talks about the future relationship right away. It's those kind of assurances we are happy to give."

However, Mr Varadkar’s deputy, Simon Coveney, struck a different tone, saying it was “wishful thinking to ignore the default outcome if nothing else is agreed; that default is a crash-out”.

Read more: Jackson Carlaw backs Theresa May's Brexit deal

He stressed: "Surely now is the time in Westminster for everyone, in government and in opposition, to cast aside unrealistic options based on promises that simply cannot be delivered.

"If that doesn't happen quickly, in the absence of that realism, it is the hardliners who think no price is too high to pay for their version of Brexit who will win out to everyone's cost, including Ireland's."

But David Davis, the former Brexit Secretary, dismissed the Irish ministers’ comments, claiming the EU would come back to the table to renegotiate the Brexit deal if the UK "holds fast" as the deadline for leaving approached.

He told BBC Radio 4's Today programme that the EU was "testing the mettle of the British Government".

The Yorkshire MP continued: "The simple truth is that they will hold fast to their line - this is the traditional approach of the European Commission, the European Union - they will hold fast to their line to the last possible minute and then, if we hold fast to our line, then they will actually come back and renegotiate."

Mr Davis added that if that occurred we should demand legal assurances and "some sort of undertaking on a free trade deal", saying: "This will get very, very sticky, very close to the end; that is what will happen. And we need to work out what is negotiable and what isn't."

Elsewhere, Mr Barclay denied reports that Article 50 could be extended, saying it would "generate some very practical issues" while No 10 was adamant that there would be no extension and Britain would leave the EU on March 29.

During the weekly Cabinet, Michael Gove, the Environment Secretary, supposedly told colleagues that some MPs were waiting for the perfect. He likened them to “mid-50s swingers waiting for Scarlett Johansen to turn up.”. At which point, Amber Rudd, the Work and Pensions Secretary, interjected to say: “Or Pierce Brosnan.”

David Gauke, the Justice Secretary, quipped: “They’re waiting for Scarlett...on a unicorn.”

The PM’s spokesman was asked Mr Gove did make the alleged comments to which he laughed and told reporters: "Next question."