JEREMY Corbyn has been accused by Tory high command of doing a “shady backroom deal” with Nicola Sturgeon to facilitate a second independence referendum should Labour gain power.

However, the claim – which will form a central plank of the Conservative election campaign north and south of the border - was swiftly denied by the Labour leader’s office as “fantasy and fake news”.

The Labour leader insisted there would be no pact with the SNP leader and he was not in favour of indyref2 “any time soon” but added: “Obviously under the terms of devolution, if the Scottish Parliament demands it, then there could be, at a much later stage, a referendum.”

The clash came as this morning Mr Corbyn launches Labour’s election campaign in London with the message that a vote for his party will be a vote against “a corrupt system” of tax dodgers, bad bosses, big polluters and billionaire-owned media holding Britain back.

“This election,” the Labour leader will say, “is a once-in-a-generation chance to transform our country, take on the vested interests holding people back and ensure that no community is left behind.”

He will promise “real change is coming,” declaring: “When Labour wins, the nurse wins, the pensioner wins, the student wins, the office worker wins, the engineer wins. We all win.”

Boris Johnson will also take to the campaign trail in southern England – on the day that Britain should have left the EU under his “do or die” pledge.

Ahead of a trio of visits, the Prime Minister promised a new Conservative Government would give the public hope and improve opportunity.

Declaring how he wanted 2020 to be a “great year for our country” with billions of pounds more investment in Britain’s public services, Mr Johnson warned: “The alternative is for the people of this country to spend the next year - which should be a glorious year - going through the toxic, tedious torpor of two more referendums on EU membership and Scottish independence thanks to Jeremy Corbyn’s incessant indecision."

Earlier at the last PMQs of the parliamentary session, the Tory leader locked horns with his SNP counterpart over Scottish independence, which the PM dismissed as a “crackpot” idea.

Noting how an economic think-tank had calculated Brexit would deliver a £70 billion annual hit to the economy, Mr Blackford claimed Mr Johnson was “willing to throw Scotland under his big red bus to deliver his Brexit no matter what the cost”.

But the PM argued the greatest damage to Scotland would come from the SNP’s “reckless plan” to break up the Union, noting how 60 per cent of Scottish exports went to the rest of the UK.

Highlighting the largest ever Treasury block grant to Edinburgh and the benefits of the “most successful political partnership in history,” Mr Johnson decried how the SNP would “throw all that away with their crackpot plan for borders at Berwick and creating a new Scottish currency or joining the euro”.

He went on: “And, worse still, going into the EU and handing back control of Scotland’s fisheries; Scotland’s spectacular marine wealth. Just at the moment they have been won back by this country, they would hand back control of those fisheries to Brussels. That is their policy; I look forward to contesting it at the barricades.”

As Scottish Conservative MPs cheered their leader, Mr Blackford predicted many of them would not be returning to Westminster after December 12.

He said: “Only a vote for the SNP can secure the escape route for Scotland away from this Brexit mess, from the chaos of Westminster and from the austerity of the Tories and protect Scotland’s right to choose our own future as an independent country in Europe.”

Mr Johnson claimed the SNP’s persistent focus on independence was a ruse to hide the truth that they were “wrecking” Scotland.

“They are diabolical for the Scottish economy,” declared the PM. “They have the highest taxes in the UK. They are not running either health or education well. That is why they are so monomaniacal about independence and smashing the Union.”

Post-PMQs, a senior Tory source turned to the idea of a pact between Mr Corbyn and the First Minister, saying: “He has done a shady backroom deal with Nicola Sturgeon for a referendum in Scotland, something which I don't think much of his party is particularly happy with but it's a position which Jeremy Corbyn has stated very clearly.”

But the Labour leader’s spokesman insisted: “The claim being made repeatedly by Boris Johnson and the Conservative Party about two referendums if there's Labour Government next year is invented and completely untrue.”

He added there would be no facilitation of indyref2 in the “formative years of a Labour government; so, we can put that claim down to fantasy and fake news”.