JEREMY Corbyn insists Boris Johnson’s denials of a no-deal Brexit meltdown “cannot be trusted” and is demanding the immediate publication in full of the UK Government’s latest impact assessment.

The ratcheting-up of political pressure on the Prime Minister comes as Downing St signalled a forthcoming PR blitz to give the public practical information about Britain’s departure from the EU and to allay fears about shortages of food, fuel and medicines if the country crashed out of the Brussels bloc without a deal on October 31.

A large-scale “user-friendly” publicity campaign, including adverts on TV, social media and in the Press is due to begin in the next two weeks. It will cover issues like food prices and availability as well as travelling abroad and passports.

Michael Gove, the Cabinet Office Minister in charge of no-deal planning, is expected to make a trip to Scotland next week to explain the Government’s strategy. He will also update MPs on their first day back following the summer recess on September 3.

Whitehall officials and UK diplomats across the EU are said to be preparing for a no-deal exit dress rehearsal, codenamed Exercise Yellow Rehearse, pencilled in for October 8 and 9, in another sign of intent to Brussels.

HeraldScotland: Camley's cartoon: Boris Johnson heads to Berlin and ParisCamley's cartoon: Boris Johnson heads to Berlin and Paris

Downing St played down concerns raised by the weekend leak of the Operation Yellowhammer file - the Government’s assessment of the impact of a no-deal outcome – saying what was published was “out of date” and preparations for Brexit had been “significantly stepped up” in recent weeks.

It also brushed aside calls from opposition party leaders and more than 100 MPs for Parliament to be recalled from its summer break early to debate what Green MP Caroline Lucas described as an “impending national emergency”.

A No 10 spokeswoman said: "The House of Commons agreed the date it would rise for summer recess as well as its return on September 3 and this was passed by a majority of close to 200 MPs."

Speaking ahead of a roundtable discussion with businesses in Hertfordshire today, Mr Corbyn said: “The Government’s own Operation Yellowhammer dossier makes the chaos and damage that will be caused by Boris Johnson’s no-deal Brexit crystal clear.

“If the Government wants to be believed that it doesn’t represent the real impact, it must publish its most recent assessments today in full. Boris Johnson’s denials can’t be trusted and will do nothing to give businesses or consumers any confidence that the dire state of affairs described in these documents aren’t right around the corner.”

The Labour leader accused Mr Johnson of being “wilfully committed” to a policy that he and his Cabinet colleagues knew would destroy jobs, hike food prices and open up the NHS to a takeover by US private companies.

“That is a price that Boris Johnson is willing to pay because it won’t be him and his wealthy donors who pay it; it will be the rest of us,” declared Mr Corbyn.

He added Labour would “do everything we can to stop no-deal, protect people’s livelihoods and pull our country back from the brink”.

On Monday, Mr Johnson, during a visit to a hospital in Cornwall, continued the Government’s effort to play down what ministers described as the “worst case scenario” set out in the leaked Yellowhammer file.

The PM said: “I'm not pretending that there won't be bumps in the road. There will be; I said that on the steps of Downing St. But if everybody puts their minds to it, I have absolutely no doubt that we can get ready."

Yet his effort to reassure people did not dissipate concerns among political opponents. Ms Lucas said Mr Johnson's "bumps in the road" were more like "cavernous sink holes".

She added: "Unless MPs get back into Parliament and hold this Prime Minister to account, we are going to go into those sink holes and it's going to spell a disaster for this country."

The Freight Transport Association, which ensures food and goods are delivered to shops and businesses, demanded an inquiry into what a no-deal outcome would mean for consumers.

The industry body was particularly alarmed by the suggestion, contained in the leaked Yellowhammer file, that it could lead to the closure of two oil refineries with knock-on shortages of fuel.

Noting how UK ministers had “not been clear with us how these things might play out,”James Hookham, the association’s Deputy Chief Executive, said: “We have been planning for queues at Dover and the disruption of trade with Ireland but this would be a new order of magnitude.”

The BBC reported internal documents from local councils, which supply food to schools and care homes, showed how they were planning to cope with a no-deal Brexit in light of possible price hikes and food shortages.

North Ayrshire Council said it "might need to amend school nutrition standards" while Hastings Council warned of the need for “rationing”. As a Brexit contingency, some Scottish councils have already increased funding for extra provision from food banks.

Andy Jones, Chairman of the Public Sector 100 Group of caterers, said: "If a no-deal Brexit happens, the supply chain long term will absolutely be under pressure. And that will affect the most vulnerable in society."

Earlier, in a keynote speech in the marginal Midlands seat of Corby, Mr Corbyn urged Remainer MPs and Tory rebels to "get on board" with his proposal that he lead a caretaker government to stop a no-deal Brexit.

The Labour leader dismissed suggestions he should step aside if a no-confidence vote brought down the Johnson Government, declaring: “All the constitutional precedents are, when a government collapses, it's the Leader of the Opposition that takes over.”

But Jo Swinson, the Liberal Democrat leader, who has suggested veteran MPs Ken Clarke or Harriet Harman as possible leaders of an interim government, tweeted: "MPs from several parties have said they will not support Jeremy Corbyn as PM, so we know he cannot command support in Parliament. If he is unwilling to get behind another candidate, then he risks delivering the no-deal Brexit he claims he wants to stop."

Ian Blackford for the SNP insisted now was the “moment of maximum opportunity” for MPs to “consign no-deal to the dustbin of history” by coming together to push a parliamentary Bill through Westminster to stop a no-deal.

He is due to meet Mr Corbyn and Ms Swinson among others at Westminster next week to plan a parliamentary no-deal strategy.

“We already know that there is a majority in Parliament against no-deal, it’s time for politicians across the House to work across party divides to bring in legislation to take a devastating no-deal Brexit off the table,” insisted the Highland MP.