In a stinging attack, the Foreign Secretary accused the hard-Left Labour leader of a “cynical and deluded” plot to keep the UK tied to Brussels forever following his abrupt policy u-turn over membership of the bloc’s customs union.
He also claimed the opposition leader had raised a “white flag” in the Brexit negotiations in an attempt to defeat Theresa May’s Government in a forthcoming vote.
“Crumbling Corbyn betrays Leave voters – and all because he wants to win a commons vote – cynical and deluded,” the Tory Cabinet heavyweight wrote on Twitter.
“Corbyn’s Brexit plan would leave UK a colony of the EU – unable to take back control of our borders or our trade policy. White flag from Labour before talks even begin.”
Mr Johnson’s broadside followed a long-awaited speech from Mr Corbyn setting out Labour’s alternative Brexit blueprint.
Speaking to an audience in Coventry, the Labour leader committed his party to campaigning for Britain to stay in a customs union with Brussels.
“Labour would seek a final deal that gives full access to European markets and maintains the benefits of the single market and the customs union,” Mr Corbyn said.
“We have long argued that a customs union is a viable option for the final deal.
“So Labour would seek to negotiate a new comprehensive UK-EU customs union to ensure that there are no tariffs with Europe and to help avoid any need for a hard border in Northern Ireland.”
He went on to claim Britain could still have “a say” in future trade deals despite being in a customs union.
“A new customs arrangement would depend on Britain being able to negotiate agreement of new trade deals in our national interest,” the Labour leader said.
“Labour would not countenance a deal that left Britain as a passive recipient of rules decided elsewhere by others – that would mean ending up as mere rule takers.”
His position was calculated to appeal to pro-Brussels Tory rebels hoping to inflict a Commons defeat on the Government in a vote on the issue of customs union membership.
Around 30 Tory MPs have indicated they could back an amendment to the Government’s Trade Bill tabled by former Conservative business minister Anna Soubry backing customs union membership.
Other ministers and Brexit campaigners joined Mr Johnson in savaging Mr Corbyn for his customs union pledge, rubbishing his claim that Britain could win new trade deals while staying in a customs union with the EU.
International Trade Secretary Liam Fox said: “This is a cynical attempt by Labour to try and frustrate the Brexit process and play politics with our country’s future – all the while, betraying millions of Labour voters.
“Labour’s confused policy would be bad for jobs and wages, it would leave us unable to sign up to comprehensive free trade deals, and it doesn’t respect the result of the referendum.
“This is another broken promise by Labour. Only the Conservatives are getting on with delivering what British people voted for, taking back control of our laws, borders and money.”
John Longworth, co-chairman of the Brexit-backing pressure group Leave Means Leave, said: “Only by leaving the customs union can Britain maximise the opportunities of Brexit – specifically helping the poorest in society by cutting tariffs on products from the rest of the world, negotiating our own trade deals and creating manufacturing jobs in free ports around the UK.
“This move suggests that the Labour Party are willing to put cynical political manoeuvres ahead of what is in the best interests of their own core voters around the country.”
Mark Littlewood, director general at the free-market Institute of Economic Affairs think tank, said: “Remaining in some form of customs union will make it almost impossible for the UK to make the most of the opportunities Brexit has to offer.
“It would prevent the UK from reducing barriers to trade with the rest of the world, whether by signing new deals or simply lowering these barriers unilaterally.”
Mrs May’s allies in Northern Ireland’s Democratic Unionist Party pledged to back the Government in the Commons vote on customs union membership.
DUP MP Sammy Wilson said: “It is clear that Jeremy Corbyn’s speech today is driven by cheap political opportunism, completely overturns previous promises made by the Labour Party during the last general election that it was opposed to membership of the customs union and is a blatant attempt to bring down the Government rather than safeguard the interests of the UK or workers in industries across the United Kingdom who would benefit from the United Kingdom’s freedom to make its own trade deals outside a customs union.
“Corbyn is hoping to capitalise on the opposition to leaving the EU from the few malcontents in the Conservative Party. He clearly hopes that they will join with him, putting personal prejudices ahead of their own party duties.
“The DUP, as we have done already, will be giving our full support to the Government to oppose this Brexit-wrecking policy which, regardless of the promises made by Corbyn, will result in the UK still being tied to regulations, directives and diktats from the EU.”
February 26th, 2018: Express