SCOTTISH ministers will not accept any “imposition” on devolved powers as a result of Brexit – insisting any move to constrain Holyrood will be rejected.

More than 100 powers currently handled by Brussels are in areas devolved to Scotland, such as agriculture and fishing.

But a protracted row over whether these should initially be transferred to Westminster or Holyrood has threatened to derail the Brexit process.

It has now been reported Downing Street is preparing to offer a concession that would see all 111 powers return to Holyrood in a bid to break the deadlock.

However, suggestions this would involve Westminster retaining a veto over the use of the powers until UK-wide “common frameworks” are agreed mean the proposal is likely to be rejected.

A spokesman for First Minister Nicola Sturgeon said the Scottish Government had consistently made clear that it is “not prepared to sign up to a deal that jeopardises or cuts across the existing settlement”.

Warning time was running out to reach agreement, he added: “I’m not aware of any particular offer that’s been made, but I would come back to the key point of principle here, which is: we’re not opposed to common, UK-wide frameworks in certain areas. We’ve said that – for practical reasons, we can see merit in certain common frameworks.

“But that cannot be by imposition. Frameworks would have to be agreed by mutual consent. And if you’re talking about an offer which involves in same way constraining the power of the Scottish Parliament in areas which are already devolved, then clearly that impinges on the existing devolution settlement, and that’s not acceptable.”

He continued: “We can’t have a situation where the ability of this parliament to legislate in these areas is constrained or in some way frozen as a result of some deal.

“Our position is that, exactly as outlined before, all devolved powers exercised at an EU level must be devolved here.”

It comes as Brexit Secretary David Davis dismissed claims Britain is heading for a "Max Mad-style" dystopia after it leaves the EU.

In a keynote speech in Vienna, Mr Davis said the UK was determined to maintain its track record of high regulatory standards – from worker's rights to the environment – after Brexit.

He said fears over a “race to the bottom” were based on nothing – “not our history, not our intentions, nor our national interest".

But Labour insisted his assurances were not worth the paper they were written on, with shadow Brexit secretary Sir Keir Starmer adding: "The truth is there are many in Theresa May's Government who want to use Brexit as an excuse to drive down standards and weaken fundamental rights."

Mr Davis is due to host talks in London on Thursday in a bid to resolve the stalemate between Holyrood and Westminster over the European Union (Withdrawal) Bill.

Ministers in both the Scottish and Welsh administrations have repeatedly described the UK government's legislation as a "power grab".

Scottish Brexit Secretary Mike Russell previously said the most recent talks, which took place in Edinburgh at the start of February, were "very frustrating".

It comes after UK Government amendments to the legislation – which had been promised while it was before the House of Commons – failed to transpire, leaving any changes to be made in the Lords.

Ms Sturgeon’s spokesman said: "Weeks and months have passed and there is still no sign of the action that was promised to try to resolve this.

"We're still talking, we're still intent on being as cooperative as possible, but time is running short and we haven't made the progress so far that we need to see."

He said the Scottish Government had “made clear” it could push ahead with its own legislation to ensure the successful transfer of EU powers after Brexit if necessary.