Boris Johnson arrives at No 10 yesterday after making his views known

Boris Johnson has challenged the prime minister to sack him by indicating that he has no intention of quitting the cabinet despite branding her favoured customs plan “crazy”.

Downing Street tried to sidestep a confrontation with the foreign secretary yesterday after he said that Theresa May’s proposed customs partnership would create a “whole new web of bureaucracy”. Friends of Mr Johnson said he would not resign. “Why should he?” asked one. “He knows it’s better to fight for this on the inside.”

No 10 said that Mrs May continued to have full confidence in Mr Johnson but declined to say whether she had spoken privately with him about his comments.

The prime minister’s spokesman added that the entire cabinet had signed up to the two