The Queen will miss today’s Remembrance Sunday service at the Cenotaph after spraining her back, Buckingham Palace has announced.

It was due to be the monarch’s first public outing after being advised to rest by doctors for almost a month, following medical checks in hospital.

In a statement, Buckingham Palace said: “The Queen, having sprained her back, has decided this morning with great regret that she will not be able to attend today’s Remembrance Sunday Service at the Cenotaph.

“Her Majesty is disappointed that she will miss the service.”

It is understood the Queen’s back sprain is unrelated to the recent medical advice for her to rest.

Her injury is believed to have happened recently and there were concerns over the impact of a car journey and a period of standing.

A royal source said: “It is obviously incredibly unfortunate timing, and nobody regrets the Queen’s absence today more deeply than Her Majesty herself.”

The source added that the Queen is “deeply disappointed to miss the engagement which she regards as one of the most significant engagements of the year”.

Sky’s royal correspondent Rhiannon Mills said there had been a “huge amount of anticipation” about whether the Queen would attend today’s Remembrance Sunday service.

The 95-year-old royal was due to watch the service at the war memorial in central London from the balcony of the Foreign Office building.

Her attendance at the service was confirmed by the palace on Thursday after she was ordered to rest by royal doctors just over three weeks ago, and spent a night in hospital on 20 October undergoing tests.

The palace had previously said it was the Queen’s “firm intention” to attend the annual wreath-laying service in Whitehall.

Mills said the Remembrance Sunday event is particularly poignant for the monarch “because she is a member of the wartime generation”.

“During the Second World War she saw her father rallying the nation as king,” Mills said, adding that the Queen’s late husband Prince Philip also served in the Royal Navy during the war.

It is understood the Queen – who will remain at Windsor Castle today – hopes to continue with her schedule of light official duties next week as planned.

A wreath will be laid on the Queen’s behalf at the Cenotaph on Sunday by Prince Charles.

He will be joined at the service by the Duchess of Cornwall and the Duke and Duchess of Cambridge.

Prime Minister Boris Johnson will also attend.