The UK is facing a “winter of discontent” after the Tories pushed ahead with Brexit, taking Britain out of the European Union, Scotland’s Deputy First Minister will warn.

With supermarkets having already experienced issues with shortages, John Swinney will argue that such problems show how “Westminster isn’t working”.

The Scottish Deputy First Minister will use his speech to the SNP national conference to hit out at the “muscular unionism” of Boris Johnson’s Conservative government – adding that the Prime Minister and his colleagues simply “do not have the brains to match the brawn”.

The Westminster government will “plaster the country with union flags” as well as “take every opportunity to undermine the Scottish Government”, Mr Swinney will say.

Supermarkets have been hit by supply problems after Brexit (Michael Drummond/PA)

The Deputy First Minister will go on to blast the Conservatives for pushing ahead with Brexit in the midst of the coronavirus pandemic, telling SNP delegates that “there is perhaps no greater example of how the Union has failed Scotland than the sorry saga of Brexit”.

Mr Swinney will say: “Despite the warnings, against the will of the people of Scotland, and in the grips of a pandemic, the Tories pressed ahead with the hardest of breaks.

“Boris Johnson once spoke of Brexit and the ‘sunlit meadows beyond’, but the reality he has delivered is food rotting in the fields because there is no one there to pick it.

“The end of freedom of movement, and the draconian clampdown of migration from the EU has been a disaster for the economy – not just here in Scotland but the whole of the UK.

“Perhaps the most obvious example is the empty shelves in our supermarkets. But staff shortages are beginning to bite across the economy.

“Last month we saw the quite extraordinary news that the NHS in England had to tell GPs to cancel blood tests due to an acute shortage of supplies.”

Mr Swinney will go on to warn: “Every sector will feel the chill wind brought on by Brexit. And there is no end in sight.

“The Tories are unwilling and unable to take the simple steps required to fix the problem they have created. The UK is facing a winter of discontent and Westminster isn’t working.”

Strikes and industrial disputes were a feature of the ‘winter of discontent’ in 1978 and 1979 (PA)

The UK so-called “winter of discontent” occurred in the late 1970s, when strikes and industrial action were exacerbated by the coldest winter for 16 years – with storms leaving some more remote areas of the UK isolated.

The then Labour government was placed under mounting pressure, with prime minister James Callaghan beaten by Conservative Margaret Thatcher in May 1979.

By referencing this time, the Tories accused the SNP of “ramping up division to distract from their decade of disasters that have hit our schools, hospitals, jobs, businesses, ferries and just about everything else in Scotland”.

Scottish Conservative health spokeswoman Annie Wells said: “The SNP blame everything on Brexit because they’ve got nothing else to say.

“No new ideas to tackle the drug deaths crisis they created, nothing to help the businesses they’ve shafted for years, and no plans to cut down on shocking ambulance waiting times.”