By James Tapsfield, Political Editor, For Mailonline
Published: 16:03 GMT, 11 February 2019 | Updated: 19:44 GMT, 11 February 2019
Michel Barnier today vowed that the EU will not make any more concessions on the Brexit deal - insisting the UK must give ground.
The chief negotiator launched a combative attack on the 'negative' British stance ahead of a meeting with Brexit Secretary Steve Barclay.
Meanwhile, Luxembourg PM Xavier Bettel jibed that the UK was actually a 'disunited kingdom', accusing Eurosceptics of only being willing to say 'no, no, no'.
The intervention came as Theresa May desperately battles to find a way through the political deadlock, with less than seven weeks to go until the exit date.
Chief negotiator Michel Barnier launched a combative attack on the 'negative' British stance ahead of a meeting with Brexit Secretary Steve Barclay
Mr Barnier was speaking after holding talks with Xavier Bettel (pictured right) - who jibed that the UK was a 'disunited kingdom'
Mrs May was today forced to quell Tory fears that she is about to cave into Jeremy Corbyn's demand for a permanent customs union with the EU.
Mrs May had caused panic in Tory ranks by appearing to open the door to a grand bargain in a letter to the Labour leader.
But her hopes of finding a way through that satisfied Tory Brexiteers was dealt another blow this afternoon as Mr Barnier said 'something has to give on the British side'.
Up to 60 Labour MPs are 'actively looking for ways' to support the PM's Brexit deal, it was claimed today.
Wigan MP Lisa Nandy said she would not support Theresa May's plans in their current form.
But she said many of her colleagues were keen to get a package agreed.
The comments came as Mrs May confirmed she is ready to give commitments on the environment and workers' rights as she woos Opposition backing.
There have also been claims the government is looking to pump money into Brexit-voting areas to secure votes.
Ms Nandy told the BBC's Politics Live 40-60 Labour MPs were 'actively looking for ways to support this at the moment'.
Mr Barnier is due to meet Mr Barclay for dinner later but warned 'clarity' on the fate of the deal must 'come from London'.
Speaking in Luxembourg this afternoon, he said: 'It's in London where they have to find the ways and means to build a positive majority between the two negative majorities that exist today in the House of Commons.
'We stand ready to give all necessary explanations and all necessary guarantees on the withdrawal agreement act, as have already done the two Presidents Juncker and Tusk.
'We stand ready to rework with the British the content of the political declaration that sets the frame.
'Maybe there's a way to explain better, to have more ambition, to put into perspective the content of the accord, and the backstop.'
Urging Mrs May to consider the 'interesting in tone and in content' Labour position, he warned 'something has to give on the British side'.
Meanwhile, Mr Bettel told the same press conference that the UK is a 'disunited kingdom' where pro-Brexit politicians lack ideas and courage.
He moaned that the ongoing uncertainty in London 'puts us in a position where we don't know what is likely to happen tomorrow'.
'The position of the Brexiteers today, to sum it up in one sentence is `No. No,