Campaigners have said the PCT's own figures show the excessive travel times facing residents on the western side of the county if the hospital is downgraded, and instead urged the PCT to choose St Richard's as the major general hospital.

"With holiday traffic, the roads became gridlocked," said Support St Richard's campaigner Abigail Rowe.

"It can easily take well over an hour to reach Worthing or Portsmouth."

The campaigners have drawn up a map using the figures produced by the West Sussex Primary Care Trust, which is making St Richard's or Worthing a major general hospital – and downgrading the other.

The map shows those on the Manhood Peninsula face journey times of more than an hour to reach their next nearest hospital, Portsmouth or Worthing.

"And that does not include the time it takes for the ambulance to reach you," added Mrs Rowe.

The campaigners have said access in and around Chichester is a key issue, and one of the many reasons why St Richard's Hospital should become the MGH.

"If you look at the ambulance response times, they meet the targets in the urban areas but are unable to meet them in the rural areas," said David Allen, a general and vascular surgeon at the Chichester hospital.

Among those facing the prospect of a lengthy journey is Easebourne mum Nicola Kalinski, whose nine-year-old daughter Katie suffers from supraventricular tachycardia, which causes episodes of a fast heartbeat, and often has to visit A&E.

"I tend to drive her there myself because it is often much quicker than waiting for an ambulance," she said.

"It would just be a nightmare if we have to go to Guildford or Worthing or Portsmouth – they are all 40 to 45 minutes away if we have a clear run.

"If there is traffic or an accident, which there very often is, it will take even longer."

She was supported by Felpham mum Tanya Rowe, whose son Kieran fell out of a first-floor window two years ago when he was five years old.

"Having St Richard's so close is vital," she said. "He could not have gone any farther."