Ten key Cabinet players have agreed Theresa May should offer the EU a bigger Brexit divorce bill settlement to speed up trade talks.
In crunch talks yesterday, Cabinet ministers including Boris Johnson and Michael Gove agreed to raise the UK's offer to leave the EU, in return for assurances on a future trade deal.
An exact figure was not discussed but it is understood to be likely Britain will have to pay in excess of £38bn.
The Prime Minister faces a fresh crunch vote on landmark Brexit legislation in Parliament today. She has now secured top-level backing to try to end the deadlock on exit negotiations.
Tory former attorney general Dominic Grieve is leading the fight to allow the EU Charter of Fundamental Rights to continue to apply to the UK once it quits the bloc.
Mr Grieve said he wanted ministers to show flexibility on the issue as his amendment was set to be debated and put to another showdown vote.
He said today: "I am hoping that the Government will make concessions on this and respond positively."
The Bill, which brings much of EU law into British law, has proved problematic for the Government as Tory rebels have threatened to join forces with the opposition and reject parts of the legislation they oppose.
With the Bill returning to the Commons during its committee stage, opposition MPs have urged Conservatives to "proudly" back the amendment on retaining the charter.
The flashpoint comes after leading Brexiteers such as Foreign Secretary Boris Johnson agreed for Mrs May to increase the UK's financial exit offer when the PM meets European Council president Donald Tusk in Brussels on Friday.
The move emerged from a two-hour meeting of the key Cabinet Exit and Trade (Strategy and Negotiations) sub-committee, which followed reports Britain was preparing to double its exit offer to £38 billion in order to get the EU to agree to open crucial trade discussions in December.
After the Cabinet talks, a Downing Street source said: "It remains our position that nothing's agreed until everything's agreed in negotiations with the EU. As the Prime Minister said this morning, the UK and the EU should step forward together."
However, it is believed no exact figure has been set, and the extra funding would only be on the table in exchange for fast-tracked talks on post-Brexit trade arrangements, and the framework for a two-year transitional deal after formal withdrawal in March 2019.
The role of the European Court of Justice in dispute resolutions during a transition period was also discussed at the Cabinet sub-committee meeting.
A number of Tory backbenchers have expressed concern about increasing the settlement offer to Brussels.
Former minister Robert Halfon told Sky News: "The public will go bananas if we end up giving nearly £40 billion to the European Union."
Mr Tusk has set a deadline of the start of next month for Britain to make further movement on the divorce bill and the Irish border issue in order for the EU heads of government summit on December 14-15 to allow talks on a future trade relationship to begin.
Number 10 has previously dismissed as "speculation" reports claiming Mrs May could be prepared to offer a further £20 billion in payments, which would bring the total sum Britain is prepared to pay to settle its liabilities to around £38 billion - well short of the 60 billion euro (£53 billion) sought by Brussels.
The move comes as former Brexit minister David Jones is set to say on Tuesday that unless there is confirmation that the EU is prepared to move on to the next phase of the process, the PM should suspend the talks and show she will not be "strung along" by Brussels.
"There is nothing to be gained by continuing to flog a dead horse," Mr Jones will tell a conference in London - which will also be addressed by his former boss, Brexit Secretary David Davis.