Michel Barnier set a deadline for Britain to concede on the divorce bill today - David Davis dismissed calls for Northern Ireland to stay in the single market after Brexit.
EU chief negotiator Mr Barnier said the two sides were 'making some progress'
The two politicians laid bare mounting tensions as they held a joint press conference in Brussels after the latest round of talks. (19459002)
Meanwhile, Brexit Secretary Mr. Davis hinted at a shift in stance by saying the UK was willing to show 'flexibility'
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Eu negotiator Michel Barnier (left) in Brussels today 
Brexit Secretary Mr. Davis said the UK was willing to show 'flexibility' in the talks
The two politicians laid bare mounting tensions as they held a joint press conference today But he also furiously rejected suggestions from Brussels that Nothern Ireland could stay in the single market after Brexit - effectively splitting the UK.
Mr Davis said the settlement 'can not amount to creating a new border in the UK'.
The Brexit Secretary reiterated his calls for the EU to agree to move on to trade talks .
But asked whether more 'clarifications or concessions' were needed over the next fortnight before a crunch European Council summit, Mr Barnier said: 'My answer is yes.'
The clashes came amid mounting fury from Brexiteers about the EU's intransigence in the talks.
A new poll Lord Ashcroft found that six out of ten Britain in Brexit talks.
The poll published today, found that 62 per cent of those surveyed thought that Brussels is not trying to get a good deal.
Leavers have reached this conclusion, the survey found.
Voters have also lost confidence in Theresa May's ability to get a good deal.
The Ashcroft poll asked people how confident they are out of 100 that a good deal will be struck - 0 being no confidence at all and 100 being absolute confidence.
In March the average answer then
Former Cabinet minister John Whittingdale said Brussels was not willing to discuss trade until the UK conceded 'everything they want'.
Mr Davis said the situation was 'serious'. 'Now is the time for both sides to move together and seek solutions,' he said. 'This is a serious issue ...
' If we are to find a way forward it requires pragmatism from both sides.
'We are willing to engage in discussions with flexibility to reach the progress needed. '
The Brussels club have been refusing to kick off the next stage of talks amid hopes they can squeeze more money out of Britain for the so-called divorce bill.
There are signs that Theresa May is preparing to contribute more cash in order to break the deadlocked negotiations and try to move on to the talks before the end of the year.
Mr. Barnier sets a two-week deadline for the UK to make concessions on the divorce bill or risk trade talks failing to start before Christmas
Mr. Davis and Mr.
The Prime Minister has been refusing to kick off the next stage of talks amid hopes they can squeeze more money out of Britain for the so-called divorce bill The Prime Minister has already € 20billion (£ 17.7bn) into the EU's coffers for a two-year transition deal which keeps the UK in the customs union and singe market.
And, as of March 2019.
Meanwhile, an internal EU document has suggested Northern Ireland obey the rules of the EU's single market and customs union to avoid the return of a hard border after Brexit.
The document said it 'seems essential for the UK to commit to ensuring no emergence of regulatory divergence from that rules of the internal market and the Customs Union '.
A framework for a solution on the border issue is another red line for the EU before it will allow trade talks to begin.
Mr. Whittingdale told the BBC's Radio 5 Live: 'The problem, or at least the perception I had talked to Barnier and the EU, is that whilst the British government has tried to be helpful - they've shifted its position, they've made an offer - essentia lly the position of the Commission and Barnier is exactly the same as where we started, and 1943 everything they want. '
There are some signs of a resolving the standoff, with reports that both sides are moving towards an agreement which would see the UK agree to pay more in return for agreement on the transition deal .
A senior EU official told the Financial Times : 'It is tactical but the situation is delicate.
' She has to move soon. '
Mr Barnier yesterday called for Britain to offer some 'real clarification' on the financial settlement.
British official is said to be confident they can agree on the divorce bill and move on to trade talks by the end of the year.
And Tory Brexiteers have signalled their support for Mrs May paying some more into the EU's budget to kick start the next phase of talks.
On MP told the paper: 'It's money down the back of the couch.'
Another said: 'There's a range of options. But if it was packaged as paying for past commitments, not market access, and if it was not too big, I think most people would go along with that. We would be free, after all. '
Bernard Jenkin, a veteran of Eurosceptic, said: 'There will be a balanced judgment to make about whether a very expensive deal is worth it.
' That depends on the quality of the deal they are promising to make at the end of an implementation period. '
Jacob Rees-Mogg, a leading Brexiteer, said it was' perfectly reasonable to give some money' but only if it is tied to a final deal.
And he warned € 60billion (£ 53bn) is 'ridiculous'.
Theresa May, pictured leaving No10 yesterday, is reportedly considering upping the amount Britain pays into the EU for the divorce bill in a bid to unblock the Brexit talks
