BREXIT “must not be assumed,” opposition party leaders backing a People’s Vote have told Michel Barnier.

In what they said was a constructive hour-long meeting in Brussels with the EU’s chief negotiator, the party leaders stressed how there was a “cross-party resistance in Westminster to the destructive Brexit being pursued by the Tories” and that while this was “being waved through by Labour” – which was not part of the delegation – “no majority exists in Parliament for the current Brexit trajectory”.

In a joint statement, the party leaders said: “With sensible politicians from all parties uniting, we pointed out to Mr Barnier that there is a genuine cross-party consensus that our exit from the European Union must not be assumed.”

Ian Blackford, the SNP leader at Westminster, who was among those who met Mr Barnier, said: “The UK Government's reckless approach to negotiations threatens livelihoods and ignores the clear wishes of the people of Scotland.

"Scotland voted to remain in the EU and we continue to press the UK Government to stay in the single market and customs union so we can protect jobs and living standards."

Sir Vince Cable, the Liberal Democrat leader, who was also part of the delegation, said he told Mr Barnier it was “time to start serious contingency planning for a People’s Vote” as MPs who backed a second referendum were “fast forming the biggest and most cohesive bloc in Westminster”.

Also in the delegation were Liz Saville Roberts, the Westminster leader of Plaid Cymru, and Molly Scott Cato, the Green Party MEP for the South West of England and Gibraltar.

Meanwhile at Westminster, Dominic Raab warned that the risk of a no-deal Brexit would be increased if Brussels engaged in a "deliberately intransigent" approach to the talks with the UK.

The Brexit Secretary also told MPs French authorities in Calais could adopt a "go-slow" approach if Britain crashed out of the EU, which would cause chaos for trade across the English Channel.

The negative comments came during Commons question-time and as Leo Varadkar, the Irish Taoiseach, bemoaned how relations with the UK had become strained because of Brexit, noting how parts of the British Establishment expected Ireland to "fall into line" after the EU referendum.

In the Commons, Mr Raab told MPs: "There certainly is a risk of no-deal, especially if the EU engage in a deliberately intransigent approach."

Theresa May claims a deal on the UK's divorce from the EU is 95 per cent complete but the Irish border remains a major stumbling block.

It has been suggested the Government is considering chartering vessels to ensure the supply of food and medicines through alternative routes if there are problems on the Calais-Dover crossing in the event of a no-deal Brexit.

Mr Raab told MPs: "We...need to prepare for the worst-case scenario, where the authorities at Calais are deliberately directing a go-slow approach, by supporting a diversion of the flow to more amenable ports in other countries."

He added the Government was looking at "all possible contingencies to ensure that in a no-deal scenario British businesses and livelihoods are safeguarded".

In response to Mr Raab's claims of intransigence, Mina Andreeva, an EU spokeswoman, said: "The European Commission does not enter into any blame games.”

During a Lords debate on a People’s Vote:

*Lord Sugar, the business tycoon, told peers leading Brexiteers such as Boris Johnson and Michael Gove should be jailed for the "lies" they peddled during the EU referendum;

*Lord Campbell, the former Liberal Democrat leader, who backs a second EU poll, said voters had been promised by Leave campaigners a trouble-free and successful exit and that the economy would prosper but they had been “failed by incoherence and incompetence” and

*Lord Callanan, the Brexit Minister, insisted there were “robust plans” to ensure border security after a report by the National Audit Office, the Government’s spending watchdog, warned of serious gaps in cover if there was a no-deal.