MANY people believe that Brexit has undermined the legitimacy of the 2014 independence referendum in which continued UK membership of the EU was assumed. But what is also becoming clear is that Brexit has shredded the 2016 Scotland Act and many of the claims made by supporters of the so-called “vow” that underpinned it.

Since 1999, under what used to be called the Sewel Convention, Holyrood has had the right to vote on acts of the Westminster Parliament that have an impact on devolved powers. MSPs have to give “legislative consent”.

An example was the 2010 Equality Act. But until the 2014 “vow”, and the Smith Commission on extending devolution, Sewel was only a convention, not a law.

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The 2016 Scotland Act, acting on Lord Smith’s recommendation, placed the Sewel Convention on a “statutory basis”, meaning, most people thought, that this was no longer just a political convention but a legal requirement.

Nicola Sturgeon believed, not unreasonably, that this meant the Great Repeal Bill (GRB) that radically alters Holyrood’s powers would require the consent of the Scottish Parliament.

The GRB will not only repeal the 1972 European Communities Act; it will also amend the 1998 Scotland Act which requires Holyrood to observe European Union laws.

At the weekend, the Scottish Brexit Minister, Mike Russell, said that he expected the Scottish Parliament to withhold legislative consent to a “hard Brexit” which excluded the UK from the single market. But the UK Government doesn’t see it this way at all.

Legal eagles are advising that the 2016 Scotland Act merely stated that the law now recognised the convention, and nothing more. It didn’t actually alter the status quo. In fact, it was meaningless gobbledegook and there is no legal requirement for Holyrood to consent to the GRB.

And even if it did, the 2016 Scotland Act only referred to instances where the UK Parliament cut across Holyrood’s existing powers; it didn’t refer to changes in the scope of the Scottish Parliament’s overall powers.

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So, according to Professor Mark Elliot, the Cambridge University constitutional law expert, Theresa May needn’t worry her head about legislative consent motions from Holyrood or Cardiff. Scottish MSPs may think they have a say, but they don’t. And anyway, since the Prime Minister is going to push through Article 50 using the pre-democratic powers of Royal Prerogative, she can by-pass parliamentary authority altogether, both in Holyrood and Westminster.

This may all make sense to constitutional lawyers but I suspect your ordinary Scottish voter will see it as the machinations of a parcel o’ rogues.

All that post-vow talk from such as Gordon Brown about Britain becoming a kind of federation in which the Scottish Parliament would be entrenched has turned out to be so much hot air; just a clever form of words. You’ll have had your legislative consent.

Brexit will reassert UK sovereignty in the most dramatic way by stripping the Scottish people of the protections of EU law they have enjoyed for 43 years.

The Scottish Parliament will be put firmly in its place. In theory all of the EU laws will remain on the statute book but they will all be provisional and subject to review and, while Holyrood may be “consulted”, it will be a one-way dialogue.

Read more: Brexit is a reserved matter for Westminster, insists Ruth Davidson

Indeed, the Great Repeal Bill itself is a piece of constitutional theatre, a mere reaffirmation of the EU referendum vote, an offer MPs can’t refuse.

The real nuts and bolts of Brexit – the single market and all of that – will be driven through using the Prime Minister’s executive authority. The GRB will not actually come into effect until Brexit is a done deal in 2019.

Mrs May has made clear that MPs and MSPs will have no say on Article 50, no say on the single market and no say over migration and free movement.

At best, Westminster will be invited to endorse a deal that has already been negotiated by the Brexit wrecking crew of David Davis, Boris Johnson and Liam Fox. The Scottish Parliament won’t even get a sniff of that.

This may all seem hunky dory from the vantage point of Oxbridge colleges and Whitehall powerpoint presentations but it is going to lead to discontent in Scotland.

It will revive all the suspicions of Perfidious Albion: that the UK remains essentially an imperial power and cannot be trusted. The Scotland Act, already tarnished, will go down in Nationalist folklore as just another attempt to bamboozle the natives.