The Prince of Wales has thanked well-wishers as he spoke publicly for the first time since the King’s cancer diagnosis.

William attended a gala fundraising dinner for London’s Air Ambulance Charity, of which he is patron, in central London on Wednesday evening.

Arriving at the dinner, William waved to people gathered outside the venue.

He said: “We really appreciate everyone’s kind messages, thank you.”

William then mingled with guests including actor Tom Cruise inside.

London’s Air Ambulance charity gala
William waved to people gathered outside the venue in central London (Jonathan Brady/PA)

William’s wife Kate left hospital last Monday and returned to Adelaide Cottage in Windsor to be with their three children after undergoing planned abdominal surgery on January 16 at the London Clinic.

At the same private hospital, the King received treatment for an enlarged prostate and was discharged the same day as his daughter-in-law but on Monday Buckingham Palace announced Charles had been diagnosed with a “form of cancer”.

The exact details of the princess’s condition have not been revealed but Kensington Palace said previously it was not cancer-related and that Kate wished her personal medical information to remain private.

The gala dinner is raising funds for London’s Air Ambulance Charity’s Up Against Time appeal, which is seeking £15 million to replace the service’s helicopter fleet by the autumn.

William is a former air ambulance pilot with the East Anglian Air Ambulance and during the event will meet crew members, former patients and supporters before delivering a short speech.

London’s Air Ambulance Charity was established in 1989 following a growing consensus of opinion that victims of serious accidents were dying because of the delay in expert medical help reaching them and the time it took to transport patients to hospital.

The service pioneered the doctor-on-board model for air ambulances and aims to bring the hospital emergency department to the scene of an incident.