THERESA May is set to have extended Brexit talks with Boris Johnson when the pair share a seven-hour flight from New York to London this evening.

The Foreign Secretary had been planning to return separately from the United Nations General Assembly but it emerged that he would now be joining the Prime Minister on her RAF Voyager jet for the flight back across the Atlantic.

On Tuesday night, Mrs May and Mr Johnson met for the first time - since the row blew up over his explosive personal Brexit manifesto penned in a 4,222-word newspaper article - when both attended a reception for Commonwealth leaders at the UN.

The PM's spokesman declined to give any details of any conversation the pair may have had at the event.

Earlier, the Foreign Secretary declared himself "mystified" by the row provoked by his Brexit article, which led to a suggestion of bad judgement from Ruth Davidson, the Scottish Conservative leader, and of “back-seat driving” by Amber Rudd, the Home Secretary.

Describing the controversy as a “snore-athon,” Mr Johnson expressed frustration, saying: “Now everyone who had previously accused me of saying too little are now saying I am saying rather too much…What I want from my critics is some bloody consistency; the great inveterate jalopies.”

But yesterday he came under fire from another source; Phil Hogan, the Irish EU Commissioner for Agriculture, who claimed the Foreign Secretary was “a diminished figure,” who was “completely out of the loop” when it came to the UK Government’s Brexit policy.

After suggestions from friends that the Secretary of State might resign if Mrs May opted for a soft “Swiss-style Brexit,” he pulled back and insisted he had no intention of doing so and that the Cabinet was a “nest of singing birds” when it came to Britain's withdrawal from the EU.

Mr Johnson conceded that Britain must "pay our dues" during any transition period as well as meeting financial demands "where our lawyers say we are on the hook for stuff".

Downing Street described as "speculation" a suggestion that Oliver Robbins, the chief Brexit "Sherpa," who moved on Monday to a role reporting directly to Mrs May, had told Germany the PM would offer to pay £20 billion in the period up to 2020 to cover gaps in the budget left by the UK's departure.

Today, the PM and her Cabinet will meet ahead of her keynote Brexit speech in Florence on Friday in an attempt to unite behind an agreed line.

However, one minister will be absent. Sources suggested David Mundell, the Scottish Secretary, will not be able to attend due to "logistics"; he was still in Argentina on a trade mission.