DAVID Lidington, Theresa May’s new Whitehall fixer, has said he is committed to "intensifying" discussions with Edinburgh on avoiding a constitutional crisis over Brexit.

His pledge came as the SNP leadership said the Tories "always promise Scotland everything and deliver nothing".

The Cabinet Office Minister, who confirmed he had spoken to John Swinney, the Deputy First Minister, on Tuesday evening, has offered to chair a Joint Ministerial Committee meeting in London in the next few weeks and to hold fresh bilateral talks in Edinburgh. Officials from both governments are said to be liaising frequently on the issue of the repatriation of powers from Brussels and common frameworks.

It is also expected that in February Theresa May will chair a plenary session of the JMC attended by Mr Lidington and others, including First Minister Nicola Sturgeon.

During Prime Minister’s Questions, Ian Blackford, the SNP leader at Westminster, took the PM to task over the failure of the UK Government to table, as promised, amendments to the EU Withdrawal Bill to allay fears of a power-grab by Whitehall when 111 powers and responsibilities are repatriated from Brussels post Brexit.

David Mundell, the Scottish Secretary, on Tuesday said it was regrettable that the amendments could not be tabled in time for next week’s Report Stage of the bill but stressed how changes would be made as the legislation went through the House of Lords.

In the Commons, Mrs May told Mr Blackford: “We are looking to work with the devolved administrations to ensure that we put the right frameworks in place so that when we come to bring any amendment forward it is being done in the best possible way in the interests of all concerned.

"I thought that had been accepted by the SNP but we will be looking to bring forward amendments in the Lords."

Mr Blackford replied: "That simply is not good enough. The Secretary of State for Scotland promised a powers bonanza for Scotland and that, crucially, amendments would be tabled ahead of next week's debate. Yesterday it was revealed that no amendments would be launched.

"The Tories always promise Scotland everything and deliver nothing. The Prime Minister has one last chance. Will she assure the House that these amendments will be tabled ahead of next week as promised?"

Mrs May insisted her Government was delivering for Scotland, saying: "The SNP say they want to work with us on the future frameworks and we are doing exactly that. They say they want Clause 11 amended and we are doing exactly that.

"[Mr Lidington] is intensifying his discussions with the Scottish Government and indeed with the executive in Wales, as part of this.

"We will be bringing forward amendments but he says that this is a Government that never delivers for Scotland. £2 billion extra as a result of the Budget, that's delivering for Scotland," she declared.

Earlier during Cabinet Office questions, Paul Masterton, the Conservative MP for East Renfrewshire, asked Mr Lidington if he had been aware that “personal assurances were given to me and colleagues that the Government would bring forward amendments to Clause 11 of the Repeal Bill and it has failed to do so?”

He added: "Can he assure me that the Government remains committed to working with the devolved administrations to find a form of words that will be agreed and allow an LCM[Legislative Consent Motion] to be passed?"

Mr Lidington assured his colleague: "I can certainly give him that commitment.

"When I spoke to the Deputy First Minister of Scotland last night I said that we were disappointed that we had not been able to reach agreement with the devolved administrations on an acceptable form of words for such an amendment but that I was committed now to intensifying our discussions with the devolved administrations to seek to reach an agreed form of words in time for proceedings in the House of Lords."

Meanwhile, former First Secretary Damian Green, Mr Lidington’s predecessor as Cabinet Office Minister was spotted watching proceedings from the backbenches.