Election 2010: The fight for the motorway marginals

Brian Brady begins a series exploring the key seats that could win or lose the general election

Their doormats must be piled high with glossy leaflets featuring photographs of beaming candidates, and their phones probably haven't stopped ringing with calls from party activists. But many voters in Britain's most marginal seats – who will decide the outcome of the general election – will not have heard of Lord Ashcroft until last week.

Yet his role in funding the Conservative campaign in key battlegrounds – which he has boasted about himself – was thrust into the spotlight as never before when he revealed he has been a "non-dom" for nearly 10 years, to the apparent ignorance of four successive Conservative leaders.

But, with fewer than nine weeks until the likely date of the election on 6 May, just what is the scale of Lord Ashcroft's sophisticated and expensive marginal seat exercise, and is it working on the ground?

Tory strategists have identified a "golden ribbon" of marginals along three busy motorway corridors: the M62, M6 and M5. Today, The Independent on Sunday launches the first of three special investigations taking the temperature in the seats where the election will be fought and lost.

Last October, a senior Tory strategist was confident enough to boast, albeit privately, that the electoral state of play was "nowhere near hung parliament territory". How was he so sure? He drew an imaginary line on a map of Britain, running from Wakefield in West Yorkshire to Greater Manchester, down the M6 to the outskirts of Birmingham, then south-west down the M5 to Bristol. There had been a surge in Tory support in these motorway seats, he said.

The Conservatives had reason to be confident then, but since the New Year the Tory campaign has appeared to be in danger of veering on to the hard shoulder. National polling showed their lead had narrowed to two points. Then, last week, a YouGov poll for Channel 4 News found that the lead in 60 Labour-held marginals had also shrunk from seven to two points over the past year.

Private polling of marginal seats shows that voters have different priorities to those in safe seats. The top three in marginal seats, in order, are: the economy, crime and immigration – helping to explain why David Cameron has shifted his focus to these "hard" areas, away from the environment and public services. The next three are education, health and local issues.

A survey of 238 marginals last autumn echoed the Tory strategist's prediction. It forecast that the Tories would take all 13 of their targeted constituencies in West Yorkshire, helping the party to a 70-seat majority. So, has anything changed today?

Alex Story, the Tory candidate for Wakefield, once represented Britain in rowing at the Olympics, and is a veteran of the Oxford and Cambridge boat race, but these achievements appear to pale in comparison with the physical endurance of his local campaign. "We are out every day from noon till five, door-knocking Monday to Saturday," he says. "We also have three telephone canvassing sessions in the week, Tuesdays, Wednesdays and Thursdays. Last month, we spoke to 3,473 people, which makes my team the hardest working in this business."

Mr Story says there have been "targeted drops" of his glossy leaflets and "one or two, non-specific" billboards "in the general area". His Labour opponents say it is "carpet bombing", using centrally produced literature.

Wakefield is way down on the Tory target list: number 151. The incumbent MP, Mary Creagh, has a notional majority of 6,537, and the city has not slipped out of Labour hands for more than 80 years. A swing of 7.95 per cent would take the seat into Tory hands. But she should be worried by the sheer weight of blue paper landing in her constituents' letterboxes, and the fact that the Tory chairman, Eric Pickles, has described the seat as "exciting" for the Tories.

In response, Labour is making a virtue of its cash-strapped situation. Ms Creagh says: "[The Tories] have had a couple of those funny 'airbrushed' Cameron posters up, but no real boots on the ground. It's not good enough."

In West Yorkshire alone, the latest party accounts reveal that Tory constituencies raised almost £150,000 in donations during the two years to last March. At least eight of them also received more than £150,000 in campaign grants from Conservative central office in 2007 and 2008. Mr Story adds: "My strategy has been to pay particular attention to Labour's seeming strongholds, our four council estates. We've had a good reception in these and other areas. My way of campaigning is simply to be relentless. As a result of this method, what was known as the Wakefield Soviet could soon become Conservative."

But is it just about money? In an area devastated by the collapse of mining and heavy engineering, largely under past Tory administrations, 13 years of New Labour have brought their own problems. Ernest Hibbert, who set up the Community Awareness Programme for Wakefield's "hidden" homeless and disadvantaged in 1997, has seen a steep increase in the number of people appealing for his help.

In the past year alone, the total receiving vital help has risen by 27 per cent – an increase Mr Hibbert blames on the impact of the credit crunch. But he does not expect any politicians to solve the problems he is witnessing on a daily basis on the streets of Wakefield.

"It's quite distressing. In one sense we are a successful charity, but the fact that we are successful shows how far our society has fallen."

Down the road in Leeds North West, amid the mostly middle-class areas of a regenerating city, Tory expectations are high. The seat, based around Headingley, was comfortably Conservative for almost 50 years until it fell to Labour in 1997 and then to the Liberal Democrats in 2005.

The seat is, in effect, a three-way marginal, and a 4.8 per cent swing would take it back to the Tories. Julia Mulligan, the Yorkshire-born Tory candidate, claims the Lib Dems are being squeezed out as voters review their positions. "We are seeing a clarification of the choice between Conservative and Labour, and a lot of previously Tory voters reassessing their allegiances." She insists that the majority of funding for the campaign has been collected locally. The accounts show that the constituency's funds doubled to £6,555 in the year to 2007, and rose again to £11,000 in 2008.

But her opponents say that they have faced the same degree of high-cost campaigning seen in other marginals. And it appears to be paying off. In Headingley, Robin Gutteridge says: "I am probably naturally Conservative, but I voted for the Lib Dems last time. I had no real affiliation to them, but everyone else was so poor. Now, I am leaning back towards the Tories. It has a lot to do with the national situation, but their campaign in the constituency has been visible, which at least makes you think they are trying to get my vote."

But Lina Marshall, a student, is less impressed. "I do not vote Tory at home and I will not do it here," she said. "I have heard they are throwing everything at this, but no one has come to my door."

In Keighley, Kris Hopkins's campaign has been helped less by the Ashcroft money than by Labour's difficulties in "selling" a new candidate to the electorate, after the sitting MP, Ann Cryer, decided to stand down after 13 years in a seat held by her late husband, Bob, for nine years. The Tory association has, however, received almost £15,000 from Lord Ashcroft's Bearwood company since the last election.

Further along the M62, the campaign in Bury North will not require significant help from Lord Ashcroft. The constituency, needing a 2.75 per cent swing to return to the Tories after 13 years in Labour hands, was progressing even before it received a gift from the political gods. The sitting (former) Labour MP, David Chaytor, faces criminal charges over expenses claims.

Bury North appears to be a classic motorway marginal, and the Tory candidate, David Nuttall, identifies key voting types – couples with young families and first-time voters, for example. But it is clear that the expenses scandal has turned an "early gain" for the Tories into a near certainty.

Next week: Greater Manchester and southwards down the M6