Look who's minding the shop while Theresa's away...

The Foreign Secretary takes over from Chancellor Philip Hammond who was the senior duty minister last week when the Prime Minister began her annual walking holiday in Switzerland.

A No 10 spokesman stressed however that Mrs May still remained very much in charge of the Government even though she was out of the country.

“The Prime Minister is very much in charge and is constantly kept abreast of what is going on,” the spokesman said.

The disclosure comes after leaked correspondence revealed that International Trade Secretary Liam Fox sought to take key powers from Mr Johnson in what was seen as the start of a new Whitehall turf war.

In a letter obtained by the Sunday Telegraph, Dr Fox argued that his newly-formed department should be given control of “economic diplomacy” to ensure there was a “holistic approach” to future trade negotiations following the vote to leave the European Union.

Downing Street refused to comment on reports that Mrs May had been “unimpressed” by Dr Fox’s attempted power grab.

“All government departments are working towards the single goal of ensuring that we get the best deal we possibly can for Britain when we leave the European Union,” a spokesman said.

“That is what the Prime Minister is focused on. That is what the rest of the Government is focused on.”

No 10 also refused to be drawn on reports that the Government may not begin the formal two-year process of negotiating Britain’s EU withdrawal - triggered by invoking Article 50 - until late next year.

The spokesman said the Prime Minister had been clear that Article 50 notification would not take place before the end of this year but gave no further detail as to the timing.

“Brexit is a top priority for this Government and it is important that we are seen to deliver the decision of the British people to leave the EU and to make a success of Brexit and that is what we are doing,” the spokesman said.