THERESA May is being urged to walk away from the Brexit talks if Brussels does not agree to talk trade in December.

Today, David Jones, the former Brexit minister, will tell a conference in London that unless there is confirmation that the EU is prepared to move onto the next phase of the process, then the Prime Minister 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, a prominent Leave advocate, will tell the Deal or No Deal event, which will also be addressed by his former boss David Davis, the Brexit Secretary.

"The UK has shown outstanding patience and goodwill since serving the Article 50 notice. It is high time the EU stopped its prevarication,” declared the former Welsh Secretary.

Labour’s Stephen Doughty, a leading supporter of the Open Britain campaign against hard Brexit, branded Mr Jones's comments a “counsel of despair”.

He added: "The Government and their Brextremist cheerleaders only have themselves to blame for the deadlock in the Brexit talks and abandoning them to leave the EU with no deal at all would be catastrophic.”

The interventions came as Mrs May and her senior colleagues met to discuss upping the initial £18 billion offer to the EU27 on the divorce bill in a bid to unblock the logjam on trade talks at the December European Council.

Sources suggested that no final figure would be offered to Brussels but, rather, there would be Cabinet agreement for the PM to go to the Belgian capital on Friday for an EU forum, where she will discuss with Donald Tusk, the European Council President, the UK Government’s willingness to increase its offer; provided the EU27 agrees to move onto the second phase of negotiations about trade.

On a pre-Budget visit to Birmingham, Mrs May again made clear Britain would “honour its commitments,” stressing that no other EU member would have to pick up the UK's tab for the current budget cycle.

However, senior Tory MP Nigel Evans warned Chancellor Philip Hammond not to “play Santa Claus” and waste UK taxpayer money on the EU divorce bill while his Conservative colleague Robert Halfon said the public would “go bananas” if Britain had to pay a £40bn settlement.

Earlier, Michel Barnier warned that Brussels would not agree a trade deal if the UK sought, post Brexit, to cut EU regulations.

The EU27’s chief negotiator stressed that the bloc wanted to strike an "ambitious" deal with the UK but noted how its national parliaments as well as the European Parliament could refuse to ratify it unless Britain committed to a "level playing field" on issues like fair competition, food safety, social protections and environmental standards.

At Westminster, MPs on Tuesday will participate in the third day of scrutiny of the EU Withdrawal Bill with opposition MPs backing a Tory rebel amendment, put down by Dominic Grieve, the former Attorney General, calling for the full protection of the EU’s Charter of Fundamental Rights in post-Brexit domestic law. The numbers could be close given the Government's slender majority.

In other developments:

*independent legal advice commissioned by MEPs suggested Northern Ireland could be given special status in the UK's Brexit deal;

*a Comres poll of 2,000 Britons suggested seven in 10 people expected tax to increase with Brexit; and

*the European Medicines Agency and the European Banking Authority, which currently employ around 1,000 people in London, are to move to Amsterdam and Paris respectively post Brexit, the EU announced following a competition among major European cities.