The Dorset force has put in a request to the government to foot the bill for the security needed for the sailing events for the 2012 London Olympics.

It is not yet known how much of the estimated final cost will have to be met by the force.

The cost of the operation in Weymouth and Portland has worried local MPs, who fear its knock-on effects.

Funding under scrutiny

The Home Office said �600m had been earmarked for Olympic policing needs.

A spokeswoman said it would "consider any proposals for Olympic funding from police forces".

She added the total sum allocated was under "continuing scrutiny in the light of the developing security assessment".

Annette Brooke, Lib Dem MP for Mid-Dorset and North Poole, said she was worried about the possible impact on frontline police services.

She added: "My greatest concern is to make sure this does come from central funds allocated for the Olympic Games and most of all that Dorset Police has the money up front.

"It's going to be such a huge proportion of their overall budget."

A spokeswoman for Dorset Police said: "We can confirm a bid of �21m has been put forward to the Home Office but this has not yet been approved and we are not expecting approval anytime soon. These things take a considerable period of time."