THE SNP leadership will today challenge Theresa May directly after it emerged she will plough on with her flagship Brexit legislation in the face of overwhelming cross-party opposition in Holyrood.

It comes after MSPs voted to reject the UK Government’s EU Withdrawal Bill, setting the stage for an unprecedented constitutional clash.

The SNP, Scottish Labour, Liberal Democrats and Greens teamed up to withhold consent for the legislation – with only the Conservatives standing behind it.

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In a speech invoking the birth of Holyrood almost two decades ago, Scottish Brexit minister Mike Russell declared: “There is a Scottish Parliament and its voice must be heard.”

Ian Blackford, the SNP’s leader at Westminster, is expected to confront Mrs May at Prime Minister’s Questions this afternoon over claims she will “ride roughshod” over the devolution settlement.

Within minutes of yesterday’s landmark vote, Scottish Secretary David Mundell confirmed the UK Government would push on with its legislation. He added: “I still think we can resolve this issue, and that remains my objective.”

First Minister Nicola Sturgeon attacked his position, arguing UK ministers wanted Holyrood “to take it on trust that they won’t act without our consent”, but had now confirmed they would.

It comes amid claims a key section of the UK legislation, which deals with the return of devolved powers from Brussels after Brexit, represents a “power grab”.

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UK ministers want temporary control over 24 devolved areas – including food labelling, agriculture and public procurement – to ensure cross-border frameworks can be set up after Brexit.

But the Scottish Government insists this could leave Holyrood unable to pass laws in those areas for up to seven years.

The Labour-run Welsh Government previously shared the position of Scottish ministers, but dropped its opposition following changes to the legislation. Yesterday, assembly members in Cardiff voted to give their consent.

Mr Russell said Scotland’s inaugural first minister Donald Dewar – often dubbed the “Father of the Nation” for his role in delivering devolution – had cautioned that the Scottish Parliament was not an end, but rather “a means to greater ends.”

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He added: “Today we are called on – for the first time – to protect those means by refusing to accept changes to them to which we have not agreed.

“To protect those means, so that we can go on achieving the best ends for Scotland we can.

“To protect those means because the people of Scotland themselves chose them – and they chose us to protect them.”

MSPs voted 93 to 30 to reject the Brexit Bill, a move which could lead to UK ministers imposing the legislation on Scotland without Holyrood’s consent. This has never been done before, and is seen as politically toxic by many.

Meanwhile, the Scottish Government is gearing up for a Supreme Court battle over its alternative Brexit legislation, which has been challenged by the UK Government.

Iain Macwhirter: What if MPs were to agree that Holyrood was right to say No?

Both sides said the door remains open for cross-party talks with UK and Scottish ministers in a bid to break the deadlock.

Mr Russell insisted he wanted to strike a deal, but warned he would not settle for “any agreement, and not at any price”.

He said giving consent to the Brexit legislation would effectively hand a veto to the Tories for seven years, allowing them to “muzzle” Holyrood.

He told MSPs: “This is not a victimless crime. While the Tories attempt to grab power in this parliament, people, interests, organisations, businesses, are suffering the chaos of the Tory Brexit – and it is being backed by the Scottish Tories.”

Speaking after the vote, he said any move to force legislation on Holyrood would break a “20 year old devolution settlement”.

He added: “The solution, as this Parliament has agreed, is straightforward. That is for the UK Government to remove the clause that fundamentally undermines devolution and to proceed on the basis of agreement.”

Scottish Tory constitution spokesman Adam Tomkins denied there was a power grab and insisted it was “frankly baffling that we are where we are today”.

He said: “It's patently obvious that Nicola Sturgeon wants a political crisis to provide cover for her independence drive.

“We will stand up for anyone – Conservative, Labour or Lib Dem – who wants to see the SNP challenged and taken on.

“The SNP has taken the wrong path today. It's deeply disappointing that the leaders of Labour and the LibDems have helped them do it.”

Analysis: Holyrood's vote means the constitutional row will continue

Scottish Labour’s Brexit spokesperson Neil Findlay MSP said: “As the party that delivered devolution Labour will always seek to defend and strengthen it – and that is why we could not vote to give consent to the EU Withdrawal Bill at this time.

“The Tories shambolic handling of this key area for Scotland is pushing the case towards the Supreme Court.

“The people of Scotland want this mess fixed and even after this vote there is still time to do that.”

Mr Mundell said he was “disappointed” by the vote, adding: “We remain hopeful that the Scottish Government will still come on board. Even at this late stage our door remains open.”

The EU Withdrawal Bill seeks to transfer all existing European legislation into domestic UK law, but aspects dealing with the return of devolved powers have proved controversial.