Theresa May being interviewed in her office at No 10 by The Sunday Times yesterday

Boris Johnson was joking but his frustration was self-evident. The foreign secretary was blunt about Theresa May’s new plan for Brexit. “It’s a big turd,” he pronounced to the cabinet. It was the morning session of the prime minister’s Friday summit at Chequers aimed at thrashing out a negotiating position for a trade deal with Brussels.

In what was described by one minister present as “a six-minute moan”, Johnson complained that May’s customs plan — in which the UK will collect tariffs on behalf of the European Union — and which the foreign secretary had thought was dead, had instead “emerged zombie-like from the coffin”.

He warned May and her spin doctors that plans to accept EU rules on the sales of goods going forward