The Prime Minister will avoid putting the final figure in writing at a summit in Brussels next month to avoid a political row, insiders revealed.
EU negotiators said Mrs May provided a clear assurance to fellow leaders that her Cabinet has agreed to pay more money after a crunch meeting last week paving the way for formal talks on a new trade agreement to be approved at the European Council meeting in December.
A senior EU source told the Sunday Times: “A deal is now doable. This is a breakthrough.
“The Brits will list categories in which they want to honour their commitments. They will present different calculations than the Commission, but for us it’s all about accepting the principle — not about having a specific figure.
“The withdrawal agreement will not contain a figure — the Brits only need to indicate what, and how. Not how much.
“It will all be about the presentation in order to help May and her cabinet deal with the political sensitivities. But the stars are aligned for a successful deal.
“We are in the business of securing an agreement. We need to improve the atmosphere in order to move on to the real difficult bit — the trade deal.”
Meanwhile, Michel Barnier, the EU chief negotiator, wants to make giving the UK a good transition deal conditional on Britain’s “automatic” acceptance of new Brussels regulations during the likely two-year period after March 2019, leaked documents show.
This would mean Britain has no say over rules made during the transition period but would have to accept them.
The demand, should it materialise, is almost certain to enrage other hardline Brexiteers such as Foreign Secretary Boris Johnson, Environment Secretary Michael Gove and Liam Fox, the Trade Secretary, as well as other Eurosceptics such as Tory MP Jacob Rees-Mogg – all of whom are against any sort of transitions deal and want a clean break with the EU.
The leaked papers, which consist of a presentation drawn up by Mr Barnier for the EU 27’s representatives, seen by The Independent, say any UK transition out of the EU must involve the “automatic application in the UK of new EU rules post-30 March 2019”.
In further controversy, Mrs May is considering a move to allow the European Court of Justice (ECJ) to keep its role in the British judicial system post-Brexit.
The PM has held talks with EU officials about a referral system to the ECJ for EU nationals who remain in the UK.
Under the proposal UK judges would refer a case to Luxembourg if a query arose on a point of law that has not previously been addressed during our time as a member state.