Ashcroft cash unleashed against Balls

Ed Balls faces a tough fight to hold on to his seat in the face of a concerted Tory decapitation strategy, a survey by The Independent has found.

A straw poll of 250 likely voters across his constituency in West Yorkshire found the Schools Secretary only marginally ahead of his Conservative challenger. When the results are weighted to take into account the outcome of the 2005 election and recent boundary changes, the poll suggests that Mr Balls would be defeated.

The Conservatives began targeting the seat in November when the seat was unofficially elevated to "battleground status", which meant that the local association started to receive some of the funds that Lord Ashcroft, the Conservative deputy chairman, directs into key constituencies. Tory strategists are hoping that even if they don't win their efforts will be enough to distract Mr Balls from the national campaign.

The weighted survey found that 30 per cent of voters said they would vote Labour, with the Conservatives ahead on 34 per cent. The Liberal Democrats saw no increase in their share of the vote, remaining at 11 per cent, while the BNP could pick up as much as 7 per cent.

Only one half of voters who backed Labour in 2005 say they plan to vote for Mr Balls on 6 May.

Mr Balls, one of Gordon Brown's closest allies, is currently the MP for Normanton, but at this election he is standing for the new constituency of Morley and Outwood after his seat was abolished in a boundary review. Experts calculate that the seat has a notional Labour majority of almost 10,000, meaning the Conservatives require a swing of more than 12 per cent for victory.

Mr Balls' main rival is the Tories' Antony Calvert, a former local councillor who is standing as a prospective MP for the first time. The party has recently opened a full-time office in the centre of Morley and have bought up dozens of poster sites across the constituency. Yesterday, the shadow Chancellor, George Osborne, paid a campaigning visit.

The Conservatives hope to deal Labour its own "Portillo moment" – so-called after the shock defeat of Michael Portillo in 1997 on a 17.4 per cent swing to Labour, a result which came to symbolise the collapse of the Conservative vote.

Former Labour voters say they are generally happy with Mr Balls' performance as an MP, but want to deliver a "wake-up call" to the party.

Others are more critical: "I see him as a watered-down career politician from the same mould as a lot of the New Labourites, using a safe seat to further his own political career," said Franco Floridia, a 45-year-old nurse living in Outwood.

One long-time Labour supporter said: "Go back to the 1980s and everything round here was desolate. People fed up with the Government won't go to the Conservatives, they'll go to the BNP or not vote at all."

Additional reporting by Rob Hastings and Tom Brooks Pollock