But despite the money coming through the doors, staff have been leaving because the hospital cannot afford to keep them on – so now it is fighting to find volunteers.

Founder Dennis Fenter was at his lowest point when the hospital was facing closure. But he has been uplifted by the support the hospital has received.

He said: "When I started looking after birds in my back garden in Rustington in 1971, I little thought I was starting what would become one of the first and largest wild bird and animal hospitals in the south of England.

"I find it very humbling that a charity started in my back garden could engender such goodwill.

"In the past three weeks, enough funds have been promised that we should be able to continue to operate at least until Christmas, although we still need to raise more funds to be sure of being able to continue beyond that.

"It was too much to expect all our staff to stay with us in a period of such uncertainty – after all they have families to feed, mortgages to pay and so on – so we have lost some staff.

"We urgently need people with ideas who can help us survive for the next 35 years."

Last weekend the fundraising peaked when the hospital opened its doors to the public.

Mr Fenter added: "We were flat out – we couldn't let any more people in."

Staff at West Sussex County Council raised £688.

They had a dress-down day, on which staff had to pay £1 to wear casual clothes.

The waste management section is sponsoring one of the owls at the hospital and staff have also been collecting animal food and cleaning products.

WSCC fundraiser Jo Thurgur said: "If, for a sake of a few pounds, the hospital closed, I would find it very upsetting."