David Cameron has set his sights on securing the first Conservative by-election gain in 26 years, pledging yesterday to put his “heart and soul” into winning Crewe & Nantwich.

The Tory leader admitted as he set off for his first visit to the constituency that it would be a setback if he failed to overturn Labour’s majority of 7,078.

Voters had the chance to send a message to Gordon Brown over the 10p tax rate, said Mr Cameron, who has made the first Tory by-election gain since 1982 his “top campaigning priority”.

But the Tory leader refused again to be drawn on how he would compensate the estimated 5.3 million households that have lost out from the abolition of the basic tax rate.

Instead, he broke new ground in seeking to empathise with hard-up voters when asked if he, like Mr Brown, felt voters’ “hurt”.

“Yes, I am wealthy,” he said. “I have a very well-paid job and so does my wife but I drive my own car, I fill it up at the pumps.”

Then, seeking to present himself as an alternative prime minister, Mr Cameron said that his three priorities were school reform, welfare reform and strengthening families.

He said that Mr Brown’s “lack of a clear plan, the lack of a proper sense of focus” meant that he could not deliver change for the country.

He said that it was too early to say whether a planned 2p rise in fuel duty should still go ahead in the autumn, but added that a decision would need to be taken soon.

Mr Cameron announced that his leadership team will work closely with Rolls-Royce to develop policies to help to develop and broaden the economy. “We want to understand in detail the factors that contribute to successful science, technology, engineering and manufacturing in the 21st century and what government can do to help put those factors in place for British industry as a whole,” he said.

“Members of our policy teams will be embedded within Rolls-Royce teams, both in the UK and internationally. We will hold a manufacturing summit later in the year to investigate how to engineer a modern manufacturing revival in this country.”

Mr Cameron hailed Boris Johnson’s “very strong start” as the Mayor of London, but insisted that the colourful Tory MP would not be under his control.

“I will be there if he wants to ask my advice, and vice versa, but it is now his mayoralty, his decisions, his appointments,” he said.

He refused to say when Mr Johnson would step down as MP for Henley, but said that it would happen “before too long”.

Vince Cable, the Liberal Democrat Treasury spokesman, said: “David Cameron is involved in the worst kind of political posturing. He cries crocodile tears for those who are losing out from the abolition of the 10p tax rate, but the only tax cuts he has proposed are for millionaires.

“If he wants to do anything meaningful to help these people, he must put forward fully costed proposals on how he would make those on low incomes better off.

“If he does not, we must assume that this is another baseless PR stunt with no foundation in policy.”

Later Mr Cameron made his first campaign visit to Crewe, arriving an hour late by train in the railway town before embarking on a walkabout through in its pedestrianised centre.

In shirtsleeves, and accompanied by his party’s candidate, Edward Timpson, 34, whose family own a shoe repair business with high street outlets across the North West, he was anxious to dispel the suggestions from Tory aides last week that his party was already writing off its chances in the by-election.

It was a “big ask”, he said, but they were throwing everything at the campaign to overturn the majority enjoyed by Labour at the last election. Climbing on to a wooden bench in the town centre, Mr Cameron adopted a triumphalist tone as he declared: “This by-election is going to be a referendum on the way that the Labour Party kicked hard-working people in the teeth with the abolition of the 10p tax band.”

He added: “Send him a message on May 22 — we want these 5.3 million people helped. We want the harm that was done to be undone.”

At one point he was confronted by Nick Burn, 47, an unemployed teacher, who challenged Mr Cameron to promise that any government that he would lead would bring back the 10p tax threshold.

Mr Cameron said he would reopen the Budget, and look at the tax codes, but he could make no such a promise.

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