Acute services in Devon and Cornwall are drawing up drastic contingency measures to cope with a mass influx of visitors for the solar eclipse in six months' time.

Police predict the population of some towns, including Plymouth and Truro, could quadruple during the two weeks straddling the solar eclipse on 11 August.

At Truro's Royal Cornwall Hospital, no elective surgery has been booked for that fortnight. And no accident and emergency department staff will be given leave during the week of the eclipse itself.

The hospital's gynaecology ward will become a major incident room, and Royal Cornwall Hospitals trust is arranging for hospitals further north to be on alert for patient transfers. Medical suppliers have been asked to deliver stocks at night.

Recent estimates on the number of visitors likely to visit Devon and Cornwall during August have ranged between 1.5 and 6 million. Discussions on how emergency vehicles will cope with the consequent rise in traffic are continuing.

Paul Westaway, Westcountry Ambulance Services trust's emergency planning officer, said: 'We are desperately trying to plan our way through the issues of gridlock.'

Police estimate that traffic management will reach a critical point if more than 2.5 million vehicles are on the roads of Devon and Cornwall. Mr Westaway said that if that happened, police would have to stop traffic at Bristol and evacuate vehicles from main roads.

The ambulance trust will borrow an additional air ambulance and five extra motorcycles to combat the problem.

Plymouth Hospitals trust has freed 2,000 beds by not booking elective surgery at Derriford Hospital for a fortnight - although some elective patients will remain on stand-by. Each of the trust's directorates is developing contingency plans 'on the basis of a worst-case scenario', said logistics manager Chris Taylor.

Staff requests for leave are on hold until a board meeting next week. Visits to its A&E department are predicted to double over the month.

The city's Royal Eye Infirmary plans to relocate some services to Derriford Hospital to cope with injuries linked to staring at the sun.

But 'unusual factors', including official and makeshift new-age festivals, are creating extra challenges.

In Plymouth, acute services are liaising with psychiatric nurses about an anticipated rise in drugs-related mental health problems.

And Mr Taylor told HSJ: 'We had some intelligence that pagans had been holding love-ins in order to have births around the time of the eclipse. I have warned the obstetricians - but we think they are more likely to be tent births so it shouldn't bother our services too much.'