residents in Lancashire face a rise in council tax for no extra service when the county's police force merges with Cumbria, it has been revealed.

While Lancashire tax payers' bills for police services could rise by 13 per cent, residents in Cumbria will be charged 22 per cent less than they are now.

The new charges have been calculated by dividing the total council tax collected in both Lancashire and Cumbria by the number of tax payers.

But because Lancashire's police council tax precept is one of the lowest in the country while Cumbria's is one of the highest, residents in the red rose county are left losing out.

The proposed rise comes after the Lancashire Police Authority was this year capped by the government to a 6.97 per cent council tax rise when members had wanted to charge 15 per cent to pay for extra officers.

But the merger plans mean that Lancashire residents will now almost be charged that amount for no extra service.

The merger is expected to cost £19million and that money is having to be recouped through savings over a four year period.

Ministers have insisted that the levelling out of two forces' council tax is the only fair way to ensure residents do not pay different amounts for the same police.

But others insist that Lancashire residents should not have to pay extra for the same level of service.

Ribble Valley MP Nigel Evans said: "The whole thing is quite horrific.

"This will cost us more and we are not getting a better service."

Lancashire Constabulary is likely to be merged with Cumbria police as part of the national move to create bigger forces in a bid to tackle terrorism and serious crime more effectively.

When the new force is launched a new council tax level for police services will be set.

At this stage it looks likely that Lancashire residents' bill should increase 13 per cent from £107.72, while Cumbria's would fall 22 per cent from £155.43 so both were paying £120.63 annually.

Coun Malcolm Doherty, chairman of the Lancashire Police Authority, said the council tax issue was one of the unanswered questions which was preventing them from officially backing the merger until they had an answer from the government.

He added: "They need to come up with a solution for that issue as it is one which sticks in most people's throats.

"But we are still a way off finding a solution. The Home Office are looking at it carefully.

"There cannot be two different tax levels because that would require new legislation.

"An option being talked about is to spread the rise over a period and the government supports with finance."