Boris Johnson is preparing for crunch talks with Theresa May amid recriminations over the Brexit blueprint that left him clashing with officials and facing criticism from colleagues.
The Foreign Secretary will head to New York for a meeting of the United Nations but he is now expected to have discussions during the visit with the Prime Minister about Britain's EU exit strategy.
Mr Johnson was accused of being a "back seat driver" after releasing a 4,000-word article setting out his vision for the UK's future outside the European Union just six days before Mrs May is due to give a major speech on Brexit in Florence.
His decision to revive the widely-criticised claim that up to £350 million a week will be freed up for public spending after Britain quits the bloc left him embroiled in a messy spat with the chairman of the UK Statistics Authority chairman.
Sir David Norgrove published a letter to Mr Johnson saying he was "surprised and disappointed" the figure had been revisited and claimed it was a "clear misuse" of official figures.
Mr Johnson responded with his own letter accusing the statistics chief of a "complete misrepresentation" of his views and called on him to withdraw the criticism.
He claimed the statistics boss had privately conceded he was "more concerned by the headline" and the coverage of the controversial article and "accepted that I was not responsible for those".
But a spokesman for the chairman stood by his accusation and said the Foreign Secretary's riposte "doesn't alter his view".
Labour's Chuka Umunna, a supporter of Open Britain group campaigning for a soft Brexit, said Mr Johnson's "outright lying" had been exposed while Sir Vince Cable praised the UK Statistics Authority for having the "courage to slap Boris down".
Mr Johnson's Brexit essay said Britain should make no payments for access to the European single market after Brexit, and made no mention of the transitional period which the Prime Minister is now thought to favour.
Amber Rudd she had been "too busy" dealing with the Parsons Green bomb attack to read the opus and criticised the Foreign Secretary for releasing the piece at the time of the blast.
The Home Secretary insisted the Prime Minister is "driving the car" on Brexit and, when pressed on Mr Johnson's actions, said: "You could call it backseat driving."
Mrs May's de facto deputy Damian Green said Mr Johnson would not be sacked over his intervention and suggested "people should calm down" after a "weekend of excitement".
Meanwhile, Jacob Rees-Mogg said Mr Johnson's article was "tremendous".
Writing in the Daily Telegraph, he said his fellow Conservative MP had "magnificently rejected" the "depressing view" that Britain could not cope without the protection of the European Union.