NICOLA Sturgeon is to meet with Welsh First Minister Carwyn Jones in Edinburgh today, as the two leaders pledge to work together to stop a Brexit power grab by the Tories.

The meeting between Sturgeon and Jones comes as a new report suggests Brexit could result in Scotland’s budget being cut by 11 per cent in just over a decade.

In a submission to Holyrood’s Finance Committee, the Chartered Institute of Public Finance and Accountancy (Cipfa) said losing freedom of movement would deprive Scotland of taxpayers leading to a a reduction in tax revenues of between £1.7 billion and £3.7bn annually.

That and the loss of long-term EU funding could see Scotland’s GDP reduced by up to £11.2bn by 2030.

Cipfa Scotland urged Scottish ministers to consider the impact during its budgeting process, and to look at policy and tax measures that could help overcome any loss in income.

Don Peebles, head of Cipfa Scotland, warned of the knock-on effect this could have on public services.

“Scottish public spending power is significantly vulnerable to the impacts of Brexit,” he said.

“As it is likely that many of the fiscal risks predicted will be realised in future years, the Scottish Government must begin to budget for Brexit so that it will be in the best position to sustain any financial shocks.

“Considering the impact of Brexit may be keenly felt in Scotland, it is important that the Scottish Government has an influence on the negotiations to ensure any Brexit deal works for its public services.”

Speaking ahead of today’s meeting, both Sturgeon and Carwyn said they had been knocked back when they asked Theresa May for some influence over negotiations.

“We have been equally clear that we are prepared to come to the table, to work constructively with the UK Government to try and reach agreement on future arrangements,” Jones said.

He added: “Based on their behaviour over the last few months, we have seen no real desire to take up this invitation and unless we see a completely different approach we will not be recommending the Assembly gives its consent to this Bill.”

By convention, the Brexit repeal bill needs the consent of the parliaments in Edinburgh and Cardiff. The SNP leader said it was “inconceivable” she would ask MSPs to back the bill in its current form.

Sturgeon said: “Both during and after the EU referendum, new powers were promised to Holyrood but instead the UK Government is planning to impose new restrictions on the Scottish Parliament.

“The UK Government’s EU (Withdrawal) Bill returns powers, even in devolved policy areas, solely to Westminster. Both the Scottish and the Welsh Governments have been clear that this power grab cannot be allowed to take place.

“I am looking forward to discussing with Carwyn Jones how we can work together to change the Bill so that devolution and the interests of the people of Scotland and Wales can be protected. As it stands, it is inconceivable that we would recommend that the Scottish Parliament gives its consent to the legislation.”

Holyrood does not have the power to stop the Bill or to derail Brexit.

However, if the Scottish Parliament does refuse to give consent, Theresa May could ultimately become the first Prime Minister since devolution to override the will of a devolved parliament, creating a constitutional crisis.

Over the weekend, Tory trade secretary Liam Fox was reportedly demanding powers to bypass the Scottish and Welsh governments on free trade agreements after Brexit.

According to a newspaper report, Fox, who resigned in disgrace from the cabinet in 2011 after allowing his friend Adam Werritty to take on an unofficial and undeclared role as his adviser at the Ministry of Defence, wrote to ministerial colleagues with proposals for negotiating trade deals.

He asked ministerial colleagues to deny devolved administrations the ability to veto deals, and to stop them sitting on May’s new post-Brexit board of trade. David Mundell, the Scottish secretary is said to have rejected Fox’s proposals.