Horrified John Lewis customers and staff watched on as a man stabbed himself repeatedly with a knife.

The police were called at 1pm and after negotiations, shot him with a Taser gun.

The man, who was in the furniture department, had stabbed himself several times and required urgent medical attention.

He had mental health problems and was considered likely to harm himself.

Olivia Finucane, from the police, said: “Officers deployed the Taser for the man’s own safety and he has been airlifted to hospital with serious injuries.

“Nobody else was injured in the incident. Officers remain at the scene as investigations continue.”

The floor of the department store, in the Harlequin, was closed as paramedics fought to save the man's life.

At about 2.30pm Harlequin staff stopped traffic in the ring road, at the traffic lights opposite Lower High Street, to allow an ambulance through.

He was then picked up by the Hertfordshire Air Ambulance, which landed in the grounds of Watford Grammar School for Girls, in Lady's Close.

Ambulance service spokesman Gary Sanderson said: “On arrival a man was found in a serious condition. Paramedics and a doctor from the air ambulance rapidly treated, stabilised and immobilised him before he was airlifted direct from the scene to a specialist trauma centre at the Royal London Hospital in Whitechapel.”

A shopper in John Lewis said: "I came in to pick up some bed linen but was told the floor was shut.

“I can't believe something like this could happen in the middle of the day, surrounded by hundreds of shoppers."

Were you in the Harlequin today? Contact the news room on 01923 216295.