DAVID Mundell has warned Nicola Sturgeon against making “naked threats and politicking” over the UK Government’s flagship Repeal Bill after she accused Whitehall of a power-grab and made clear Holyrood should not give its consent in the present circumstances.

The Scottish secretary suggested the SNP would pay a heavy price at the ballot box if it tried to “hijack” the process for its own ends, saying how such a move would “not play particularly well with the people of Scotland”.

The legislation, the first of eight pieces and entitled the European Union [Withdrawal] Bill, scraps the 1972 European Communities Act, which took Britain into the Brussels bloc, and will transpose some 12,000 EU laws into UK law.

Hours after its publication, it ran into difficulty not only with the Nationalists but also with Labour, which made clear it would vote against the legislation unless it was amended to include guarantees on devolved powers and human rights.

The Liberal Democrats, meanwhile, predicted that in the months ahead the Conservative Government faced parliamentary "hell" over the bill and that the "political nightmare" facing Theresa May could cost her her No 10 job.

Far from accepting the UK Government was intent on a power-grab, Mr Mundell insisted it was offering Scotland a “power bonanza”.

He said there would be the return of significant powers and responsibilities to the Scottish Parliament currently exercised by the EU.

The secretary of state explained there would be a "transitional arrangement," whereby the powers would first come to Westminster to ensure a consistency of UK-wide frameworks and would then go to Holyrood.

"Needless to say there will be a process row with the Scottish Government because the Scottish Government does process row; that is their speciality,” he declared.

But he pointed out how such a process row had occurred in relation to the Scotland Bill and the fiscal framework yet they had delivered what the UK Government had promised: more powers for Holyrood.

However, Michael Russell, the Scottish Government’s Brexit minister, recently made clear MSPs agreeing to grant a Legislative Consent Motion[LCM] – whereby Westminster legislates on their behalf on devolved issues - in relation to EU withdrawal was “not a given”.

Earlier this week, Ian Blackford, the SNP leader at Westminster, stressed how the Scottish Government wanted to co-operate with Whitehall but warned that if Theresa May continued with her intransigence towards a hard Brexit, then options would have to be considered; including the possibility of Holyrood refusing an LCM.

Following the bill’s publication, Mr Mundell told The Herald how the legislation was important to ensure certainty as the EU laws were transposed into Scots law. “So naked threats and politicking, things we’ve come to be used to from the SNP, are unnecessary; what I’m interested in is a sensible dialogue”.

He asked, if the First Minister and her colleagues were unhappy with the UK Government’s mechanism for leaving the EU, what was their alternative?

“Are they simply looking to hijack this bill to make some broader point. I don’t think that would play particularly well with the people of Scotland.

“The SNP are facing an election in 2021. It’s quite clear from the UK General Election that their positioning on these issues has not found widespread support; their vote fell, they lost 21 seats, they came within 600 votes of losing another six seats. I don’t think people in Scotland will respond well to politicking with this bill,” declared the Scottish secretary.

Ms Sturgeon, who was in Brussels for talks with Michel Barnier, the EU’s chief negotiator, alongside her Welsh counterpart, Carwyn Jones, issued a joint statement soon after the Brexit legislation was published, saying how it had utterly failed the test on whether or not the Prime Minister was adopting a more collaborative and co-operative approach.

"We have repeatedly tried to engage with the UK Government on these matters and have put forward constructive proposals about how we can deliver an outcome, which will protect the interests of all the nations in the UK, safeguard our economies and respect devolution.

"Regrettably, the bill does not do this. Instead, it is a naked power-grab; an attack on the founding principles of devolution and could destabilise our economies," claimed the two First Ministers.

Also in the Belgian capital for a meeting with Mr Barnier was Jeremy Corbyn, who held two hours of talks as part of his bid to present himself as a prime minister-in-waiting; ready to take over the EU withdrawal process if there were a change of government.

Describing the meeting as "very interesting, very frank," the Labour leader decried any attempt to use so-called Henry VIII powers, where there is not full scrutiny, to push through parts of the legislation.

"Far too much of it seems to be a process where the Government will decide through statutory instruments and therefore will be able to bypass Parliament. We will make sure there is full parliamentary scrutiny,” declared Mr Corbyn.

Labour, in part, said it would vote against the legislation unless it were amended because it stated the European Charter of Fundamental Rights would not be put into UK law after Brexit.

But ministers believe the charter rights are already contained in EU rules, which the legislation will convert into domestic law on the day of withdrawal.

Elsewhere, No 10 signalled it might be prepared to make concessions on the bill with a spokeswoman stressing: "We want to work with all parties, MPs, devolved administrations, and talk to them. This bill is simply about making sure that we have a functioning statute book when we leave.”

The first key Commons vote will take place in September.