The Queen will miss another event on the third day of Platinum Jubilee celebrations as a host of royals stepped out without her on Friday (local time) for a special church service.

Queen Elizabeth, who is suffering “mobility issues” and using a walking stick, stayed at home in Windsor Castle and watched day two’s National Service of Thanksgiving at London’s St Paul’s Cathedral on television.

She was represented by heir Prince Charles, while much attention was focused on Prince Harry and Meghan, who were making their first public appearance together in Britain since stepping down from royal duties two years ago.

The Queen’s heir Prince Charles, with wife Camilla, represented his mother. Photo: Getty

Buckingham Palace confirmed the 96-year-old monarch, who has been feeling “discomfort”, would also miss Saturday’s 243rd Epsom Derby, which she normally attends and which together with a pop concert outside Buckingham Palace will comprise the third day of Jubilee celebrations.

As with the Thanksgiving service, the Queen will watch the Derby on television.

The Duke and Duchess of Cambridge arrive at the thanksgiving service at St Paul’s Cathedral. Photo: Getty

Friday’s church service, which followed the fun and thrills of the opening Trooping the Colour and military flypast on day one, recognised the Queen’s lifetime of service and included 400 special guests such as politicians, charity figures and groups the Queen has supported.

Prime Minister Boris Johnson, who delivered a reading, was met by a mixture of cheers and boos from the crowd outside the cathedral, reflecting recent public anger over his conduct in office.

British media commented that the boos were more prominent than the cheers.

All eyes were on Prince Harry and Meghan as they walked the length of the aisle to take their seats. Photo: Getty

Harry, 37, and Meghan, 40, arrived to a smattering of boos, but also loud spontaneous cheers, and appeared slightly nervous as they held hands tightly, with the eyes of the congregation fixed on them as they walked to their pews.

They were seated on the opposite side of the aisle to the Duke and Duchess of Cambridge and alongside Princess Eugenie and her husband Jack Brooksbank on one side.

On the other side was Princess Margaret’s daughter Lady Sarah Chatto.

There was no obvious interaction between Harry and his brother William at Friday’s service.

The California-based couple, who had said they were “excited and honoured” to attend the Platinum Jubilee events, made headlines with a bombshell Oprah Winfrey interview in March last year.

Their relationship with the other royals, most notably with Harry’s elder brother Prince William, has been frosty since Meghan, who is biracial, accused an unnamed royal of racism and Harry complained his family had cut them off financially..

Media reports suggested the Queen had finally met baby Lilibet for the first time on Thursday, though a palace source described this as complete speculation.

During the sermon, Archbishop of York Stephen Cottrell referenced the Queen’s love of horses as he described her enduring reign.

The National Service of Thanksgiving at St Paul’s Cathedral. Photo: Getty

The Archbishop said her 70 years as head of state was like the distance of the Grand National — the famous, gruelling steeplechase — rather than the Epsom Derby sprint.

“But with endurance through times of change and challenge, joy and sorrow, you continue to offer yourself in the service of our country and the Commonwealth,” he said.

“Your Majesty, we are sorry that you’re not here with us this morning, but we are so glad that you are still in the saddle. And we are glad that there is still more to come. So thank you for staying the course.”

The service featured Bible readings, prayers, and hymns to express gratitude for Elizabeth’s reign.