Tory Eurosceptics are expected to vent their frustration at Theresa May on Tuesday over the Government’s lack of clear vision for Britain’s future outside the EU.

Boris Johnson, the Foreign Secretary, has openly challenged the Prime Minister to drop the customs partnership deal – under which the UK would collect tariffs for the EU after Brexit – saying it was a “crazy system” that would make it “very difficult to do free trade deals”.

No 10 confirmed Mrs May’s Brexit war cabinet had delayed a decision from a meeting this Thursday on whether Britain will back the customs partnership, or adopt a more light touch customs arrangement.