The Conservatives are diverting campaign money and resources away from constituencies that they believe they will easily win, as growing poll leads increase the scale of the party’s electoral ambitions.

Candidates in Labour seats that would fall to the Conservatives on a swing of only a few hundred votes are being told that their seats are in a category comfortingly termed “sure win”.

This means that they face having their funding cut because they are no longer deemed in need of help from Conservative Central Office.

The increasing likelihood of victory for the Conservatives at the next election has prompted the party to consider diverting resources away from seats it believes are already in the bag to those previously regarded as unrealistic prospects.

They include seats such as Dagenham, which is currently 164 on the hit list. The Conservatives would need a swing of just over 8 per cent to capture the seat, which was held by Labour’s Jon Cruddas at the last election with a majority of 7,605. Other seats that could benefit from the new funding priorities include Luton South, number 140 on the list, and some seats in Kent. Sitting Labour MPs are already understandably rather nervous about their electoral prospects in these seats.

All of this implies that the Tories are hoping for a swing of between 6 and 8 per cent at the next election. That is in line with the latest Populus poll for The Times, which gave the Conservatives a 13-point lead over Labour — a swing of about 6.5 per cent — though other polls have given the party leads of approaching 20 per cent since the Budget.

If the Populus poll reading were replicated on election day, the Tories would win 140 to 170 target seats, giving them a majority of between 50 and 80 seats in the House of Commons. Until now the Conservatives have set themselves the target of winning at least 100 seats.

Alan Cullens — who is fighting Chorley, 152 on the Tory list of most winnable seats — said there was a perceptible shift in tactics in the second half of last year. “The seat has become more of a target since late last year. The higher the polls, the higher your targets go,” he said.

Mr Cullens has had a big campaign project funded by Conservative headquarters in the past six months, and also received visits from George Osborne, the Shadow Chancellor.

Another candidate in a more ambitious marginal told The Times yesterday that Conservative campaign headquarters (CCHQ) interest in his patch had been growing.

“There’s definitely a feeling that the focus is starting to shift towards seats that, two years ago, would have been long shots but are now seen as very winnable,” he said.

So far he had received a few thousand pounds from Conservative headquarters, he said, though the flow had gradually increased over the last two years.

“I certainly feel that the spotlight is shining more than it did before. I’m not privy to all of the private polling data but I do view it as a good sign that the head office is more interested and I am keeping my fingers firmly crossed,” he said.

The strategy is being masterminded by Lord Ashcroft, who was brought back inside the party to run the Target Seat campaign in the summer of 2007, when David Cameron was on the back foot in the row over his policy on grammar schools.

Lord Ashcroft’s team includes Stephen Gilbert and Gavin Barwell, himself a candidate in the ultra-marginal seat of Croydon. All three are regarded as supremely powerful figures by the party’s parliamentary candidates.

Strategists at CCHQ have divided constituencies into six categories. These include a set number of “battleground seats”, which receive tens of thousands of pounds in campaign funding.

More ambitious target seats are called “development seats”, but they receive substantially less campaign money — usually just a few thousand pounds.

Those that are seen as likely to fall without the need for a large cash injection are labelled “sure wins”, and candidates in those seats also only receive limited support.

Party candidates are expected to present a business plan for their campaigns to Lord Ashcroft’s team in order to secure the money.

When deciding how much they will receive, the target seats team makes an independent assessment about the suitability of the candidate and viability of their plans to take the seat at the election.

They also take into account other factors, such as recent local election results and the possibility of private funding.

Typically, the money is used to pay for advertising campaigns in the local media and to set up websites. Funding for direct mail shots — which are the most expensive campaign tool available to most candidates — is seen as the best possible outcome.

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