The royal family is to put on a united front at the Princess of Wales’s carol concert on the day the Duke and Duchess of Sussex’s final Netflix episodes air.

The King, Queen Consort, Prince of Wales, Kate and other family members will be out in force in public to support the princess’s Together At Christmas festive celebration at Westminster Abbey on December 15.

The royals will be bracing themselves for bombshells when Harry and Meghan’s six-part docuseries premieres this Thursday with the first three episodes, with the last three coinciding with Kate’s Christmas service next week.

In a trailer released on Monday, Harry spoke of a “dirty game” where there is “leaking” and “planting of stories” and “a hierarchy of the family”.

But the teaser appeared to use footage of the press filming events unrelated to the couple to depict them being hounded by paparazzi.

Kate’s carol concert, supported by The Royal Foundation, is dedicated to the late Queen, who died three months ago, but comes at a time of continued turmoil for the Windsors.

Kensington Palace said: “This year’s carol service is dedicated to Her Majesty Queen Elizabeth II and the values Her Majesty demonstrated throughout her life, including duty, empathy, faith, service, kindness, compassion and support for others.

“These principles are shared and personified by the inspirational guests who have been invited to the Abbey in recognition of their tireless work to help and care for those around them.”

It will also “recognise the selfless efforts of individuals, families and communities across the UK, and celebrate and showcase the joy that human connection and togetherness can bring”.

Those performing include Craig David, Alexis Ffrench and Samantha Barks, as well as Alfie Boe and former Spice Girl Melanie C, who will sing a duet.

“Poignant readings” will be delivered by speakers including heir to the throne William, Dame Kristin Scott Thomas, Hugh Bonneville and Kadeena Cox, the Palace said.

The service will be broadcast on ITV1 on Christmas Eve as part of a Royal Carols: Together At Christmas programme, narrated by Catherine Zeta Jones and featuring an introduction by Kate and tributes to Queen Elizabeth II.

In a trailer for Harry & Meghan, the duke discusses the “pain and suffering of women marrying into this institution”, with his words accompanied by footage of both his mother Diana, Princess of Wales, and Kate, before she married William, being surrounded by photographers.

Harry tells how he was “terrified, saying: “I didn’t want history to repeat itself” and “no-one knows the full truth. We know the full truth”.

Billed as a Netflix global event, the streaming giant has promised an “unprecedented and in-depth documentary series” where Harry and Meghan “share the other side of their high-profile love story”.

Against a backdrop of Harry’s long-reported rift with brother William and troubled relationship with Charles, Meghan’s accusations that Kate made her cry in a disagreement over a flower girl dress and claims from both that an unnamed royal made a racist remark about their unborn son and the institution failed to help a suicidal Meghan, the series is expected to further damage the Sussexes’ relationship with the King and his family.

Harry and Meghan signed lucrative deals – thought to be worth well over £100 million – with Netflix and Spotify after quitting the monarchy and moving to the US in 2020.

Directed by two-time Academy Award-nominated and Emmy-winning director Liz Garbus, the series will explore “the clandestine days of their early courtship and the challenges that led to them feeling forced to step back from their full-time roles in the institution”.