The Prince of Wales has hailed the success of a £15 million fundraising appeal to replace air ambulances serving London.

William is patron of London’s Air Ambulance Charity, which launched the Up Against Time appeal to fund a new fleet of helicopters for its service.

In a posting on X, formally Twitter, the prince wrote: “Fantastic News! This is going to have a life-saving impact.

“A huge thank you to everyone who donated W.”

Hollywood star Tom Cruise and Arsenal FC manager Mikel Arteta were among the guests at a gala fundraising dinner in February for the charity’s appeal.

The prince, a former pilot with the East Anglian Air Ambulance, attended the event and in a speech highlighted the urgency of the cause: “Here in London, the current aircraft have served magnificently. But our capital city needs a new fleet.

“And we are Up Against Time. The clue really is in the appeal’s name. By September, we need the two new red birds – decked with the latest kit such as night vision – in our skies.”

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.