Julie Spence has accused the Government of "short-changing" the force by relying on out-of-date population figures which fail to take account of rapid migration.

Cambridgeshire is currently served by 183 officers per 100,000 population. The national average is 266.

The top cop claims a squeeze on funding based on out-of-date and inaccurate population figures has put an effective cap on cash for officers in the past five years.

Mrs Spence is being joined by the Police Authority in putting forward a detailed case to ministers and officials arguing that an urgent change is needed in the way grants are calculated.

Mrs Spence said: "We've been short-changed for a number of years, losing money as the population continues to grow.

"The profile of the county has changed dramatically and this simply isn't taken into account when Government allocates funding.

"We now deal with people from many different countries, speaking more than 90 different languages. While the economic benefits of growth are clear we need to maintain the basic public services infrastructure which means increasing the number of officers we have."

The Chief Constable insisted that the force is delivering a good service with the resources it currently has, but added: "We've been doing more for less as effectively as we possibly can. But it really is unfair when we see some areas receiving much more central government funding while it is left to local taxpayers in Cambridgeshire to make up the shortfall.

"We could achieve much more if the discredited funding formula was removed and we received additional funding for around 25 officers a year between now and 2016, when the official population will jump by more than 12 per cent."

In its report "The changing demography of Cambridgeshire: implications for policing" the Constabulary and Police Authority argue that actual population growth has been ignored by Whitehall. The report highlights that:

* Migration will have a greater impact on the population than natural changes - with new communities accounting for 64 per cent of growth in Peterborough and 73 per cent of growth in Cambridgeshire as a whole

* By 2016 there will be 25,200 more people in the county as a result of 'natural' growth and people moving from within the UK to Cambridgeshire. A further 69,000 people are predicted to move to the county by 2016 as a result of migration, mainly from Europe

* Overall Cambridgeshire's official population will jump by 12.5 per cent by 2016 - whereas across the UK it will be 2031 before a 12 per cent increase is experienced.

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