Organisers of outdoor summer community events like Oxford's Cowley Road Carnival face big hikes in their insurance premiums.

And in some cases the extra costs could jeopardise the future of such events or eat into charity funds - according to the committee behind Woodstock's biggest ever carnival, held last Saturday.

Robert Edwards, of the Woodstock Carnival committee, said this year's event could be the last because of the 270 per cent increase they had to pay.

In 2006, they had to fork out a £450 premium to get a compulsory £5m public liability insurance. The premium rose this year to £1,200 for £10m worth of cover.

The change was passed down from the county council, as highways authority, because of the need for road closures. If someone was injured because a motorist ignored or was unaware of the street being closed, there could be an insurance claim.

Ian Nolan, of East Oxford Action, which runs the Cowley Road Carnival, underlined the extra cost now facing organisers.

"It is a significant increase, bumping up the cover we need to take out from £5m to £10m in one leap. It's the highways authority who are asking for it," he said.

"But it's happening everywhere, with local councils demanding the extra insurance. We are able to get funds from BMW, the Arts Council and the city council, but there's still a shortfall in the budget which we have to raise in collections on the day."

The Cowley Road Carnival, on July 1, involves road closures similar to Woodstock, where 4,500 people attended the evening event.

Carnival chairman Dennis Allen said: "The event is done on a shoestring and to have our premium bumped up by so much at such short notice is a big blow. We have to raid our reserves to meet it.

"There could be the very rare event like a motorist turning a corner and not being aware that the road is closed.

"But I don't think anyone in Woodstock on Saturday would have been unaware that there were people on the street enjoying them- selves."

The carnival committee said they were only informed about the rise just over a week before the event. They had to dip into their limited reserves to get insurance in time.

In Banbury, the town's carnival was cancelled in 2004 because of insurance and risk assessment problems and has not been revived. And last year the Banbury Show fell victim to the same problem.

Rose Sutton, chairman of Wallingford Carnival held last weekend, said: "There are far too many rules and regulations which seem to be designed to kill off public entertainment like carn- ivals."

The county council said it has been obliged, like all local authorities, to increase its public liability insurance to cover road closures.

Deputy area engineer Paul Wilson said: "Public liability insurance is not exempt and this is the situation that councils and public authorities across the country find themselves in with regard to events such as the Woodstock Carnival.

"It's not surprising that organisers are complaining. NNo organisation or individual is ever happy when an insurance premium rises and affects them directly or indirectly."