The Princess of Wales is to miss a Trooping the Colour rehearsal as it was confirmed the King will take part in his official birthday celebrations.

Kate will not inspect the troops at the event known as The Colonel’s Review on June 8, held seven days ahead of the famous ceremony which has marked the sovereign’s birthday for more than 260 years, it is understood.

But it remains unclear whether the princess, who is undergoing chemotherapy after a cancer diagnosis, will attend Trooping the Colour, a major fixture in the royal calendar.

She appealed for time, space and privacy for her family when she announced on March 22 she was being treated for an undisclosed form of cancer.

The Prince of Wales gave a positive update about his wife’s treatment during a visit to the Isles of Scilly earlier in May, saying “she’s doing well” when questioned by a hospital administrator.

During the Trooping ceremony, held on Horse Guards Parade in Whitehall, it is understood the King will carry out the review of the Guardsmen and officers from an Ascot Landau carriage with the Queen.

The change from last year’s ceremony, where Charles inspected the troops on horseback, reflects earlier Buckingham Palace briefings where it was highlighted that each engagement by the King would be reviewed and adaptations made when advised by doctors.

Lieutenant Colonel James Shaw, Brigade Major of the Household Division, who designed this year’s Trooping spectacle, said confirmation of King’s presence was “wonderful”.

He said: “Firstly, that’s fantastic news but, secondly, that means we have to step our game up even more.

“It’s just wonderful. I think the King’s service at the moment is an inspiration to us all, he’s our Colonel-in-Chief so the birthday parade needs to be even better than normal.”

The King had been carrying out a busy programme of engagements since it was announced just over four weeks ago he would be returning to public facing duties.

Rishi Sunak’s decision last week to call a surprise summer General Election has meant the monarchy has postponed any engagements “which may appear to divert attention or distract from the election campaign”.

Charles is likely to travel by carriage with the Queen during the traditional procession to and from Horse Guards Parade, and is expected to watch the Trooping ceremony seated on a dais, rather than on horseback.

The colour which will be “trooped” past the massed ranks of guardsmen and officers will be from Number 9 Company, Irish Guards.

Kate will be represented at the Colonel’s Review by General James Bucknall who will act as the chief inspecting officer of the day in the princess’ absence.

Republic, the anti-monarchy group, has said it will stage the latest in a string of protests near Buckingham Palace on the day of Trooping the Colour.

Graham Smith, Republic’s chief executive officer, said: “Rather than see royals wear uniforms, rank and medals they’ve not earned, let’s put real military personnel front and centre.

“Instead of celebrating this undemocratic institution, let’s celebrate the people of this great country.”