Boris Johnson could quit over 'crazy' customs union plan

However, his public denouncement of plans being personally pushed by the prime minister is the clearest public test of her authority yet by a senior member of her cabinet and is likely to prompt a public response from May's spokesman when he appears before journalists on Tuesday lunchtime.

Speaking on the BBC's Andrew Marr Show, Clark, who was at that meeting, and was reportedly close to tears, said the customs partnership model meant goods, could be imported without any checks at the border or paperwork.

"As part of the work over the next few weeks I think it would be a mistake to move from one situation and to another and to a third", he said, arguing that ministers could improve the two options while admitting they both have drawbacks.

With deep divisions emerging in Theresa May's Cabinet over the hybrid customs partnership proposal, the CBI's director-general Carolyn Fairbairn welcomed Clark's intervention and called for "pragmatic solutions, not ideology".

Her spokesman told reporters May still had "full confidence" in her foreign minister, Boris Johnson, after he described what is seen as her preferred plan for a customs partnership as "crazy".

Brussels has already rejected both of these customs models.

One parliamentarian who visited Westminster recently said he was surprised by how confident MPs were that there could be a frictionless border between north and south without a customs union. On Sunday he insisted that the partnership idea was far from dead.

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What are the government's options?

"Hundreds of thousands of jobs across the United Kingdom depend on it", she added.

Greg Clark, the UK Business Secretary, also signalled that the transition period on future customs arrangements might last until 2023 as it would take time to set up the necessary technical infrastructure.

The system would not help the United Kingdom take back control of our trade policies, laws, borders or our money, he added.

"I was talking this week to the global president of Toyota motors", Mr Clark said.

But Mr Rees-Mogg dismissed those concerns, telling ITV's Peston On Sunday: "This Project Fear has been so thoroughly discredited that you would have thought it would have come to an end by now". At the cabinet's Brexit subcommittee meeting on May 2, the Brexiteers urged May to abandon her preferred option of a customs partnership, which, according to critics, could tie the United Kingdom to European Union rules. "And what we would like to see from the European Union is less rhetoric and actually more engagement in relation to a pragmatic way forward, not just for Northern Ireland but for the whole nation as well".

The discarded plan would see officials track shipments into the United Kingdom, collecting tariffs for Brussels on goods ending up in the EU.

She told The Andrew Marr Show: "We believe that there are ways to deal with this, and indeed, back in August of a year ago, as you know, the Government put forward various proposals". The UK voted in a referendum to leave the European Union on June 23, 2016, and last March, May officially invoked Article 50 of the Lisbon Treaty, launching the process of the country's withdrawal from the bloc.

  • Adam Floyd