OVER the course of the next decade Theresa May’s Brexit deal will bring down living standards, and lead to a £100 billion collapse in the UK’s GDP, according to the first analysis of the Prime Minister’s draft agreement.

The scrutiny, carried out by the independent think tank, the National Institute of Economic and Social Research and commissioned by the People’s Vote campaign, suggests that this is “roughly equivalent to losing the annual output of Wales or the output of the financial services industry in London”.

In their analysis NIESR modelled different Brexit scenarios against a baseline of staying in the EU.

They say their key finding is that “if the Government’s proposed Brexit deal is implemented so that the UK leaves the EU customs union and single market in 2021, then by 2030 GDP will be around 4% lower than it would have been had the UK stayed in the EU”.

This is equivalent to a loss of 3% GDP per head, worth around £1000 per person per annum to people in the UK.

NIESR say this is because trade barriers will “make it less attractive to sell services from the UK”.

In return this will “discourage investment” and “ultimately means that UK workers are less productive than they would have been if the UK had stayed in the EU”.

The weaker economy and the smaller population, as well as an increase in unemployment, will mean higher welfare bills, leaving government revenue 1.5–2% lower in the long run, roughly equivalent to £18–23 billion.

In another staggering statistic the economists claim the total trade between the UK and the EU will fall by an incredible 46%.

If the UK were to stay in a customs union with the EU, or if the Irish backstop position was to be invoked, there would still be a hit to GDP per capita of 2%.

Another scenario, favoured by some Brexit supporters, of an “orderly no deal” departure from the EU would reduce GDP by 5.5%, or £140bn, they said.

The NIESR admit their estimates, while thoroughly researched, are uncertain as “there is no historical precedent of a country leaving a major trading block such as the EU”.

One of the report’s authors, Garry Young, said: “Leaving the EU will make it more costly for the UK to trade with a large market on our doorstep and inevitably will have economic costs. We estimate the long-run cost of leaving the EU on the Government’s preferred deal to be roughly equivalent to losing the annual output of Wales."

LibDems leader Sir Vince Cable, who supports the People’s Vote campaign for a second EU referendum, said: “Nobody voted for less control or to be worse off but somehow the Government have managed to come up with something that will achieve both.”

Last week, David Mundell refused to say if May’s deal would leave Scotland better off.

Appearing on the BBC’s Good Morning Scotland programme, the Tory minister could only say the consequences would not be as cataclysmic as a hard Brexit.

Asked to say if people will be better of as result of the deal, he replied: “What I can say is that people will be better off with this deal than a no deal which is the alternative.”