Winchester traffic chiefs are pressing for potentially controversial "park-and-share" sites on land near to the M3, the Daily Echo can reveal.

Surplus land close to junctions nine, ten and 11 could be converted into car parks that would be used by commuters.

Council bosses argue that "park and share" could help reduce congestion on the increasingly congested motorway.

A "park-and-share" scheme involves commuters driving to the possibly free car park, leaving their vehicles and getting into one car before completing their journey.

If it went ahead Winchester would be among the first in the country. But the idea would be highly controversial.

"Among the only available sites are small fields off Spitfire Link, near Winnall, and St Catherines Way near Chilcomb.

Environmental campaigners see any development on the other side of the M3 from Winchester as encroaching into the open countryside, setting a worrying precedent.

Alan Jowsey, head of traffic and transport at the city council, has written to the Highways Agency supporting the idea. Mr Jowsey said: "This is an idea we have put forward and discussed with the Highways Agency. It would be aimed at drivers heading for Basingstoke, Southampton or London. The aim is to reduce traffic on the M3.

"We are not proposing any specific sites at this stage. The obvious sites are land too small for agriculture but adjacent to the motorway.

"There's the unused car park at Tesco, other industrial units at Winnall."

The large Tesco car park off Easton Lane, is already believed to be the base for unofficial car-sharing into Winchester city centre.

His view is supported by city councillor Richard Knasel, portfolio holder for economy and transport. Cllr Knasel said: "We think it is a good idea that ought to be looked at. But we would need government financial help."

Keith Story, of the Winchester Meadows Conservation Alliance, fought a long battle against the extension of park-and-ride at Bar End, close to the field at St Catherines Way.

He said: "We would be concerned about the intrusion into the countryside.

"It would just encourage more car use and lure people off public transport. If you build lots of new car parks and make it free, the cars will come."