The Queen may have to cut short her summer holiday if she is needed to carry out any of her constitutional duties amid speculation her new prime minister could draw her into a political crisis.
The palace will not directly comment on whether political matters could see her returning early.
However, the fact she remained in Buckingham Palace to appoint Boris Johnson as prime minister was a clear display of her commitment to put constitutional duties first.
Her Majesty arrived at Balmoral in Aberdeenshire on Tuesday to start her annual summer break.
She delayed her trip to Scotland to oversee the handover of the prime ministers on 24 July.
It appears that returning to London early is not out of the question considering the uncertainty of what will happen when parliament returns on 3 September.
The Queen does not normally return to Buckingham Palace until the start of October.
Following speculation this week that Mr Johnson may not step down even if he loses a vote of no confidence, Sir Malcolm Rifkind, the ex-foreign secretary, warned he could be leading Britain into its biggest constitutional crisis since the civil war.
The Tory grandee urged the new prime minister to reject the advice of his advisers and not follow the lead of King Charles I, who suspended parliament in 1628.
Labour’s shadow chancellor, John McDonnell, has threatened to send the Labour leader to the palace in a taxi if Mr Johnson refuses to step down in the event of a no confidence vote.
Speaking at the Edinburgh Fringe, he said he did not want to “drag the Queen into this” but would “send Jeremy Corbyn in a cab to Buckingham Palace to say we’re taking over”.
Robert Hazell, professor of government and the constitution at University College London, said that the Queen has over 60 years of experience and is used to dealing with a crisis.
However, he said the current political situation is unparalleled – even to her.
He said: “There have been previous high and low points like the Suez Crisis or like the ‘annus horribilis’ when Windsor Castle burnt down, but I can’t think of any previous year in the Queen’s long reign which has seen quite such dramatic political events.
“I certainly cannot think of any previous occasion when people have seriously speculated that she might be required to dismiss the prime minister.”
During her summer break, the Queen will be kept up to date with all the latest political business via her private secretaries, one of whom is always with her in Scotland.
She receives red boxes full of political papers and briefings every day of the year, except on Christmas Day and her birthday.
The Queen’s private secretaries will be working behind the scenes through all the potential scenarios that could unfold once parliament returns after the summer break and the countdown continues to Brexit deadline day on 31 October.
The role of the private secretaries and their constant discussions with Number 10’s private secretary and the cabinet secretary will be invaluable for making sure the Queen is kept above the political fray and protected in her role as guardian of the constitution.
Professor Hazell believes the importance of those well established links should not be underestimated, especially at times of political uncertainty.
Boris Johnson insists Brexit is happening on Halloween – come what may. He said: “That network of the three private secretaries, which has been called the golden triangle, is incredibly important.
“It is one of the centrepieces of the British constitution and they work very closely together and they do try and anticipate every possible scenario so that they are well prepared.
“[They] can give the best possible informed advice when events unfold. I think potentially this is a bigger crisis than any that the Queen has faced in her long reign, but we’ll wait to see how events unfold.”
