THE SNP have hit out at the UK Government’s “unacceptable” refusal to publish an impact analysis on the Brexit deal, despite having done so for other trade agreements.

It comes after Boris Johnson’s official spokesperson repeatedly refused to give a straight answer when asked if the government would publish a formal assessment.

The spokesperson yesterday said the Government had “set out the detail of the [Brexit] deal, and the opportunities and benefits it provides the UK”, adding: “We’ve been clear it’s a good deal, which allows us to maintain access to the EU market.”

The UK Government has been suppressing at least 50 internal studies on the impact of Brexit and the benefits offered by alternative trade deals since at least 2017, according to reports in The Independent.

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Alan Winters, professor of economics at the University of Sussex, said that these studies would doubtless have been published if the Government “thought it had a very strong case that these [post-Brexit trade] deals would be big and strong”.

Winters said the most likely reason the Tories will not publish these internal assessments is that they show Brexit’s damage to far outweigh any benefit.

Echoing that sentiment, the SNP have now branded Westminster’s continued refusal a “desperate attempt to cover up the devastating damage being done by the Tories' failing right-wing isolationist project”.

The party’s shadow international trade secretary, Drew Hendry MP, pointed to Scottish Government analysis which estimated Boris Johnson's deal could cut Scotland's GDP by 6.1% - costing £9 billion, or the equivalent of £1600 for every person, by 2030 compared to EU membership.

The National: Boris Johnson may have 'got Brexit done', but his Government is refusing to look at how much it costBoris Johnson may have 'got Brexit done', but his Government is refusing to look at how much it cost (Image: PA)

One month before the Brexit deal was agreed, the independent Office for Budget Responsibility said a free-trade deal with the EU would cut Britain’s GDP by 4% in the long run, compared to staying in the bloc.

Commenting on Westminster's refusal to publish its own impact analysis of the Brexit deal, Hendry said: "The Tory Government's Brexit deal has already inflicted hardship upon businesses, people's livelihoods and the economy. Refusing to publish the impact assessment of its trade deal with the EU is only an admission that the Tories have signed up to a deeply damaging deal.

"Dodging scrutiny and accountability have become the hallmark of Boris Johnson's Government.

“Despite publishing similar reviews of other trade deals it has signed, its refusal to do so here is unacceptable and a desperate attempt to cover up the devastating damage being done by the Tories' failing right-wing isolationist project.

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"We know fine well that Brexit will leave us poorer and worse off. It's clear that the only way to properly protect our interests, economy and businesses is to become an independent country and to regain the benefits of EU membership."

Michael Gove recently caused a Twitter storm after he inadvertently seemed to admit that Brexit had a cost. This stood in stark contrast to his previous position, when he said he “absolutely” refuted the idea that Brexit would cost anything.

Instead, Gove insisted: “There are a number of economic forecasters that have made it clear there are benefits.”

The UK Government claimed it would be "impossible" to produce a model estimating the impact of Brexit.

A spokesperson said: “We have consistently said it would be impossible for a single model, number or scenario to capture the complexity of the outcomes of the deal or represent the varying impacts that will be felt across different parts of the economy.

“We have secured a zero tariffs, zero quotas deal that will benefit families and businesses across the UK, and we can now take full advantage of the opportunities available to us.”