The Duke of Sussex has hailed the “extraordinary strength and spirit” of young people with complex medical conditions as he appeared in a video calling for WellChild Awards nominations.

Harry’s brief on-camera message was released on the same day he lost a High Court challenge against the Home Office over a decision to change the level of his personal security when he visits the UK.

The duke is to seek to appeal against the ruling, his lawyers have announced.

Harry, looking relaxed in a grey shirt and wearing his leather cord necklace, urged the public to put forward the names of the “remarkable individuals who inspire you” for the charity’s 2024 awards.

The duke said: “The WellChild Awards is our chance to celebrate the extraordinary strength and spirit of young people with complex medical conditions from across the United Kingdom.

“It allows us to shine a spotlight on the resilience and positivity that they demonstrate every single day, and recognise the incredible support from the families, friends, and the professionals around them.”

He added: “It is such a privilege to honour the immense courage and compassion of this incredible community.

“But to do that, we need you to take a moment and nominate the remarkable individuals who inspire you.

“Your involvement makes a huge difference so please join us in celebrating the amazing superstars who will be recognised at the 2024 WellChild Awards.”

Harry has been patron of WellChild since 2007 and the annual awards celebrate the inspirational qualities of the UK’s seriously ill children and young people.

The duke, who appeared to have filmed the video at his home in California, attended the event in person in London last year, on the eve of the first anniversary of the late Queen’s death.

It is Harry’s first appearance on screen since his Good Morning America interview in which he spoke about the King’s cancer diagnosis.

The duke told the US breakfast show “I love my family” and that he was “grateful” to be able to spend time with his father after he flew to see him following news of his illness.

The duke spent around 30 minutes with Charles at Clarence House before the King left for Sandringham.

The royal family has had a difficult start to 2024, with the King being treated for cancer, the Princess of Wales undergoing abdominal surgery and the sudden death, announced on Tuesday, of Lady Gabriella Kingston’s husband Thomas Kingston at the age of 45.

Guests at last year’s WellChild awards included McFly’s Danny Jones, presenter Emma Willis, comic Catherine Ryan, actor Tom Felton and presenter and host Gaby Roslin.

The categories are Inspirational Child or Young Person, Inspirational Sibling, Nurse, Outstanding Professional and Inspiration Parent Carer.

Nominations can be made at www.wellchild.org.uk/awards and the closing date is March 18.