Boris Johnson has attacked proposals for a customs partnership after Brexit as "crazy" in a major public intervention over the way forward in the exit plan deadlock.
Britain's Foreign Secretary said proposals favoured by Theresa May would create a "whole new web of bureaucracy".
During a visit to the United States, he said forging ahead with the option would not comply with promises to take back control, and would hamper the UK's ability to strike trade deals.
Divisions over how to proceed erupted at a “war cabinet” where Brexiteers rejected the customs partnership option. But they believe a revised version will be put forward by the British government.
Theresa May is attempting to achieve a deal that sees no hard border between Northern Ireland and the Republic, which will be the only land frontier between the EU and the UK when the UK leaves the union next year. Ms May also needs a deal that will see no border between Northern Ireland and the rest of the UK and one that will allow Britain to negotiate its own trade deals and one that allows trade with the EU to be as frictionless as possible.
The Irish border issue has dogged progress in the Brexit negotiations for months. Earlier this month, EU's chief negotiator, Michel Barnier said there was a "real risk" that the EU and UK will fail to agree a deal on Brexit without a solution to avoid a hard border in Ireland. He said Brussels was preparing for all options, including the possibility that it cannot reach a deal with London on the UK's departure in March 2019.
In an interview with the Daily Mail, Mr Johnson said of the partnership proposal: “It’s totally untried and would make it very, very difficult to do free trade deals.
“If you have the new customs partnership, you have a crazy system whereby you end up collecting the tariffs on behalf of the EU at the UK frontier.”
Britain's Business Secretary Greg Clark stressed on Sunday that thousands of British jobs depend on frictionless trade with Europe, in what was viewed as an attempt to revive the customs partnership model.
The “war cabinet” met last week, but failed to reach agreement on whether to back the hybrid customs partnership — which would see the UK collect import duties on behalf of the EU for goods arriving via British ports and airports — or the so-called “maximum facilitation” or “max fac” model relying on the extensive use of technology to minimise checks at the border.
It comes as Mrs May faces two more parliamentary defeats on her Brexit plan as it nears its final stages in the House of Lords.
Peers want to remove the planned exit day of March 29th 2019 from flagship legislation that takes Britain out of the European Union. A second amendment would allow EU laws to be replicated in the UK and allow future participation in its agencies.
Both proposed changes to the EU Withdrawal Bill have cross-party support in the upper chamber, which means they are likely to win in a vote.
The legislation returns for its sixth and final day at report stage in the Lords and will return for third reading on Wednesday.
Shadow Brexit minister Baroness Hayter of Kentish Town said: "On the final day of Lords Report, the main focus of our cross-party efforts to ensure the Bill is fit for purpose will be twofold.
“First, to ensure the UK continues to have strong working relations with EU agencies post-Brexit — something entirely in line with the Prime Minister’s recent Mansion House speech.
“Second, to introduce greater flexibility into how we leave the EU than currently allowed for by the Government’s ‘fixed exit day’ amendment.
“Introduced during the Commons stages of the Bill and driven no doubt by political PR, putting such a definitive deadline into law could have a negative impact on the final round of negotiations.
“On both issues, there is nothing to stop ministers coming forward with late concessions.
“Failing that, and as we’ve seen over the past few weeks, Peers won’t be shy in giving MPs further opportunities to scrutinise the fine detail of this Bill.”
So far, the Government has suffered 10 defeats at the hands of peers, including over a customs union and giving a decisive say to Parliament on the Brexit talks.
Meanwhile, a further change has been proposed to the legislation that would require the Government to negotiate continued membership of the EEA.
Labour peers will be ordered to abstain because it goes against official party policy. - PA