The Tories' new plan for victory: 80 seats that will decide it all

Party draws up strategy to gain 40 and hold 40 key constituencies at 2015 general election

The Conservative Party has drawn up plans to "gain 40" and "hold 40" key marginal seats in an attempt to secure an overall majority at the 2015 general election.

Although most of the 80 crucial seats will see traditional battles between the Conservatives and Labour, the Tory strategy involves "lovebombing" voters in seats held by the Liberal Democrats rather than launching full frontal attacks on Nick Clegg's party.

David Cameron told a reception at this week's Conservative Party conference in Birmingham: "At the last election, we had to target 120 seats or more. We won 100... Next time, we only have to target 40. We are going to put a campaigner into every one of those seats."

A Conservative Research Department document says: "We have a plan, we call it the 40-40 strategy. At the next election we will have a much smaller battleground than at the last election – just 40 seats to hold and 40 to gain. With effective targeting and an incumbency advantage, we are confident that we will win outright."

The Conservatives won 306 seats at the 2010 election, 20 short of the winning post of 326 needed to secure an overall majority. They have not published their plan and say they are still finalising their list of targets. But a Tory source told The Independent yesterday that the party was eyeing up constituencies including Labour-held Bolton West, Southampton Itchen and Wirral South and three Liberal Democrat-held seats – Wells, St Ives and Solihull.

At a private briefing on the 40-40 strategy at the Tory conference, Stephen Gilbert, the Prime Minister's political secretary, told activists that the Liberal Democrats would be heavily targeted despite being in coalition with their party. But this would be by "lovebombing" rather than the heavily negative campaigning of the past. About 10 of the 40 target seats are held by the Liberal Democrats.

The Tory hit list will not be based purely on the most vulnerable and winnable seats arithmetically but will also take account of local factors. For example, the Tories are already targeting Eastleigh, held by Chris Huhne, the Liberal Democrat who resigned as Energy and Climate Change Secretary in February.

Campaign managers will also be installed in the 40 seats the party is defending in a drive that will be directed by the Conservative campaign HQ in London rather than left to local activists. The number of targets may be raised from 40 to around 70 at a later stage.

Mr Cameron told activists that he was confident his party could win an overall majority next time even though the Liberal Democrats have blocked the introduction of new constituency boundaries, which could have handed the Tories an extra 20 seats.

John Curtice, professor of politics at Strathclyde University, said: "There is no doubt that the only way in which the Tories can hope to buck the disadvantage posed by the current boundaries is for them to perform disproportionately well – and/or their opponents disproportionately badly – in marginal seats."

He added: "The party might hope that its can concentrate its efforts in fewer seats this time around because it is so much closer to the 326 mark than it was before 2010.

"However, any such concentration is only likely to prove decisive if the party has a national poll lead close to the seven-point one they enjoyed over Labour in 2010."

The plan: Where strategy will play out

Tory held marginals

Warwickshire North Former soldier Dan Byles, a fan of Boris Johnson, will defend a majority of 54.

Camborne & Redruth George Eustice, Eurosceptic former press secretary to David Cameron, has a slender majority of just 66 over the Lib Dems.

Broxtowe Held by Anna Soubry, the newly-appointed Health Minister and an ally of Kenneth Clarke who holds the neighbouring seat.

Watford Rare three-way marginal won from Labour by Richard Harrington in 2010.

Hastings & Rye Held by Amber Rudd, parliamentary aide to the Chancellor George Osborne and a former banker.

Tory targets

Bolton West Will be heavily targeted as Labour's Julie Hilling has a majority of just 92.

Solihull Natural Tory territory seized by Lorely Burt, chair of the Lib Dem parliamentary party and seen as vulnerable.

Southampton Itchen John Denham, parliamentary aide to Ed Miliband, is standing down in 2015.

Wells Captured by Tessa Munt for the Lib Dems in 2010.

Morley & Outwood A long shot, held by the Shadow Chancellor Ed Balls with a majority of 1,101.