The move is meant to help limit the scale of opposition to the vote while buying time as negotiations continue with European Union leaders.
Mrs James told the BBC's Politics Live that she expected MPs to "coalesce" around the PM's Brexit deal "or something very similar", saying: "This country can not afford to leave the European Union with no deal".
That is why I have signed a cross-party letter calling on the Prime Minister to ensure that the United Kingdom doesn't crash out of the European Union in what would be a catastrophic, "no-deal" scenario.
Last month, May pulled a vote on the brokered withdrawal agreement, settled on in November after more than a year of back-and-forth negotiations between London and Brussels, acknowledging it would have been roundly rejected by the UK's lower chamber House of Commons.
At this moment, she doesn't have the votes in her own party to get the deal approved and would need a significant number of Labor votes to succeed.
As MPs returned from their Christmas break, government sources and leading Brexiteers said there was no sign of backbench hostility to her Brexit blueprint fading.
The Democratic Unionist Party, which props up May's government, was always going to vote against her plan because it's concerned the backstop arrangement would put Northern Ireland on a different regulatory footing to the British mainland.
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She told BBC's Andrew Marr Show: "What we'll be setting out over the next few days is a sort of assurances, is measures in three areas".
Theresa May is pinning her hopes on avoiding a humiliating Brexit defeat next week on securing a commitment from the European Union that it will complete a free trade deal with Britain by 2021.
Meanwhile, Taoiseach Leo Varadkar said over the weekend that while it would be in Ireland's interests to see the withdrawal agreement accepted, ultimately, it is a decision for the British parliament at Westminster.
Pro-Remain MPs are targeting the Government's finances as part of a last-ditch effort to prevent a no-deal Brexit, taking inspiration from the USA government shutdown now suffered by Donald Trump.
In the Commons, Sir Bill Cash said: "Reassurances are going to get nowhere and they are certainly not going to convince anybody who's thinking hard about this when it comes to the vote next week".
Britain began rehearsals on Monday (Jan 7) for the upheaval of a no-deal Brexit by lining up 87 trucks at a little-used airport for a trip towards the United Kingdom's most important trading gateway to continental Europe.
The UK's central bank has warned that Britain's gross domestic product could shrink by up to eight percent in such a scenario.
"The EU has made clear that this is the deal that is on the table", she said.
In a letter published by United Kingdom newspaper the Mail on Sunday, May warned critics of her departure plan risk damaging Britain's democracy and weakening its economy by opposing her deal.
And she again rejected calls for a second referendum, saying it would be disrespectful to people who voted for Brexit in 2016.
When the undecided and those who refused to answer were removed from the sample, the split was 54-46 in favour of remaining.