Prime Minister Tony Blair's local police force could be forced to axe up to 100 front-line officers because of Government spending cuts, it was claimed today.

Durham Police, who maintain law and order in Mr Blair's Sedgefield constituency, today warned the drastic action would have to be taken because of a budget squeeze.

The force said more than 100 officer posts could be left unfilled if Government cuts went ahead over the next two years.

Letters outlining the difficulties have also been sent to the county's seven Labour MPs, including the Prime Minister. County Durham has a record number of bobbies on the beat and is recognised as one of the best performing forces in Britain.

Year-on-year falls in recorded crime make it one of the country's safest places to live.

Deputy Chief Constable Jon Stoddart said: ''The tragedy of the economic pressures facing us is that we are literally the victim of our own success.

''Over the last decade we have, through over 600 efficiency initiatives, generated more than £12 million in savings and budget reductions and we have had for many years, and continue to have, the lowest council tax precept of the non-metropolitan forces in England and Wales.''

Durham Police has been told that it will need to make savings of at least £6 million over the next two years because of the way the Government funds police forces.

''85% of our annual budget goes on staff,'' Mr Stoddart said.

''If we are forced to further squeeze finances, cutting the number of front-line officers is a possibility we may not be able to avoid.''

A delegation headed by Durham Police Authority chairman Anne Wright, and Chief Constable Paul Garvin, has visited London to lobby Co Durham MPs to fight for more funding.

Mrs Wright said that while the Government's capping formula did apply to all police authorities, it unfairly penalised those like Durham who exercised care with their spending.

She said: ''Setting the budget this year was extremely difficult and our advisers tell us we will have to make savings of at least £6 million over the next two financial years unless there are changes.

''Things are becoming critical in terms of the authority's ability to plan budgets sensibly.

''Any loss of police officers will impact on crime levels and detections, reducing the force's ability to protect our communities.

''The MPs we met acknowledged our plight and were sympathetic to our need to secure long-term financial stability. ''We have since taken up the cause with both Government ministers and senior civil servants.''

North Durham MP Kevan Jones said that under current funding criteria Durham was ''at a significant disadvantage'' compared with other forces.

He said: ''Durham Constabulary is one of the top performing police forces and has made my constituency a safer place to live in.

''I am concerned by the thought that these achievements could be jeopardised by crude funding arrangements that fail to reflect the force's needs.''