An accompanying 43-page Conservative Research Department analysis - a treatment generally reserved for Labour - follows a confidential study by the department last September.
A leaked copy of the research says: 'The Liberals pose a very positive threat to the Conservatives indeed.'
Some 'university' seats were vulnerable to swings of less than 10 per cent and had elected a Tory MP 'largely on sufferance in 1992, fearful of Labour's expenditure plans and trusting that the Conservatives would address the social agenda'.
It comments that the 'rhetoric' of John Patten, Secretary of State for Education and the MP for Oxford West, was 'not going down at all well'.
An examination of the Liberal Democrats in local government also revealed them to be a 'powerful and ever-growing force' with a formidable campaigning record.
But Sir Norman Fowler, Tory party chairman, also played the 'fear of Labour' card strongly at yesterday's press conference, insisting: 'Where the Liberals hold the balance of power, they put Labour in.'
Spotlighting another theme that will be played up during the campaigns in the shires and in the Newbury parliamentary by- election, Sir Norman said: 'These elections will take place against the background of unmistakable signs that the economic recovery has begun.'
He defended the Conservatives against a list of councils produced by Paddy Ashdown on Wednesday, where the Tories had allegedly linked up with Labour to keep the Liberal Democrats out. There were only two formal Conservative-Labour agreements, in Stockport and Calderdale, Sir Norman said, and these were of limited duration to ensure budgets were set.
He added: 'On 6 May voters throughout England and across Berkshire, not least in Newbury, need to know that a vote for the Liberals is a vote for a deeper shade of red. In Berkshire, the Liberals put Labour into power as soon as they got the chance, even though Labour had only 18 out of the 76 seats on the council and the Conservatives had more than twice as many.' A Liberal Democrat spokesman rejected that version of events.Reuse content