Staff shortages mean critically-ill patients will have to travel further to their nearest hospital sooner than expected.

The accident and emergency department at Crawley Hospital will only take minor injuries after 9pm from the end of this month rather than August, as originally planned.

The service is shutting at night eight weeks early because the hospital has been struggling to find nurses and A&E doctors.

The move has infuriated people already angry at the plans to downgrade the department to a 24-hour minor injuries centre in August when patients will be sent to East Surrey Hospital at Redhill.

Michael Edwards, who was part of an unsuccessful campaign for a new hospital in Crawley, said: "It's bad enough losing the department but to do it even earlier is worse.

"People have raised a lot of concerns about this, including ambulance workers who are also unhappy and say lives could be put at risk.

"How can a town the size of Crawley not have its own fully functional A&E department? It's ridiculous."

Sussex Ambulance crews have already warned the changes will mean longer journeys of up to 20 miles for some patients in the Horsham and East Grinstead areas.

Crawley MP and former nurse Laura Moffatt said she had previously been told the move was so patients would get a better service and that staff shortages were not a major factor.

She said: "Crawley Primary Care Trust appears to imply the issue for them is a difficulty in recruitment. Contrary to the implication in the letter, this is not something that has been raised with me in the past."

Mrs Moffatt said she would be raising the subject with Deputy Prime Minister John Prescott.

A spokesman for the Surrey and Sussex Healthcare NHS Trust, which runs Crawley Hospital, said: "We are changing the way it provides emergency care on the grounds of best clinical practice.

"We have decided to phase these changes in from the end of June as we are having some difficulties providing full staffing overnight at Crawley Hospital A&E."