British Prime Minister Theresa May backed her foreign minister Boris Johnson after reports he could quit over her Brexit strategy, it has been reported.

Sky News reporter Beth Rigby said on Twitter that, when asked whether Mr Johnson should be sacked, Mrs May said: "Boris is doing good work as Foreign Secretary."

It comes after Mr Johnson dismissed suggestions he might resign as British Foreign Secretary and denied the Cabinet is split over Brexit, insisting: "We are a nest of singing birds."

He spoke out amid reports he might quit over differences with Mrs May about the kind of Brexit deal the UK should strike.

His comments came after days of speculation about rifts at the top of government sparked by the publication of his personal blueprint for Brexit in the Daily Telegraph at the weekend.

Asked if there was a Cabinet split on Europe, Mr Johnson said: "No, we are a Government working together. We are a nest of singing birds."

And asked directly if he would resign, he replied: "No."

Mr Johnson said: "We are working together, that is the key thing, to make sure that Britain can take advantage of the opportunities of Brexit."

Mr Johnson is due to see Mrs May for the first time since his Telegraph article as the pair attend the United Nations General Assembly in New York.

Mrs May's Cabinet will meet on Thursday to be briefed on her plans for Brexit ahead of a major speech on the subject in Italy on Friday.

Today, she said she was confident of getting her whole senior team of ministers to back her Brexit strategy. 

A Telegraph report - dismissed as "mischief" by allies of the Foreign Secretary - suggested Mr Johnson would be prepared to quit by the weekend if Mrs May concedes too much to the European Union in her efforts to secure a trade deal.

Mr Johnson's intervention - and speculation about his future - has dominated the run-up to the crucial Brexit speech being delivered by Mrs May in Florence.

Billed as the PM's most important update to the government's position since January, the speech is thought likely to include an attempt to break the deadlock over the UK's financial settlement.

Speculation has been mounting she will offer to pay tens of billions of pounds to the EU during a two to three-year transition deal after the UK's formal exit in 2019.

Mr Johnson is understood to accept the idea of the UK paying its dues to Brussels during a transition period - but not for continued payments for access to the European single market on a permanent basis.

Veteran Tory Europhile Ken Clarke said Mr Johnson should have faced the sack for his Brexit intervention.

Former chancellor Mr Clarke said: "Sounding off personally in this way is totally unhelpful and he shouldn't exploit the fact she hasn't got a majority in Parliament, and he knows perfectly well that normally the Foreign Secretary would be sacked for doing that - and she, unfortunately, after the general election, is not in the position easily to sack him - which he should stop exploiting."