Brexiteers break ranks to attack customs partnership

He added that 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 during last week’s Brexit war cabinet where Leavers rejected the customs partnership option.

It is believed Number 10 is working on a revised version of the proposal.

In an interview with the Daily Mail, Johnson said: ‘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.’

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.

A hybrid customs partnership would see the UK collect import duties on behalf of the EU for goods arriving via British ports and airports. Another option discussed at the cabinet meeting was the ‘maximum facilitation’ or ‘max fac’ model relying on the extensive use of technology to minimise checks at the border.

Leading backbench Leaver Bernard Jenkin also heaped pressure on the prime minister predicting May would be forced to drop the plan.

Speaking on the Today programme he said: ‘I think the prime minister is very anxious to try to bring the whole party together around some kind of compromise proposal and the argument is going on about this. I think in the end she will have to drop it because it will prove unworkable.

‘I think it is a bit of an act of self-deception to say that we are leaving the customs union but we are still going to apply the common external tariff to all the imports coming in from the EU.’

The interventions come as 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 Prime Minister’s planned exit day of March 29, 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.