LABOUR was plunged into gloom when a shock poll suggested it will fail to win its key Westminster target seat in the North-East.

Conservative James Wharton is poised to cling on in Stockton South, the Survation survey found – despite his wafer-thin majority of just 332.

The constituency is number seven on Labour’s target list for the entire country and one Ed Miliband’s party would expect to win easily, if it is to triumph on May 7 next year.

But the poll, of 1,084 voters, gave the Conservatives a two-point lead, putting the party on 39 per cent, Labour on 37 per cent, UKIP on 18 per cent and the Liberal Democrats on just three per cent.

Despite the collapsing Lib Dem vote – and the rise of UKIP – it did not appear that voters are switching directly between the two parties.

Instead, the pollsters found that Nigel Farage’s party is snatching voters from both Conservative and Labour, while unhappy Lib Dems transfer to both the big two parties.

The only glimmer of hope for Labour was that Stockton South residents put the NHS - Ed Miliband’s top priority - as their key issue, ahead of jobs and immigration.

Intriguingly, the poll was commissioned by the Labour-sponsoring Unite union, as part of its campaign against the Transatlantic Trade and Investment Partnership (TTIP) including the NHS.

That prompted a conspiracy theory that it had been deliberately leaked by the union, which has been urging Mr Miliband to change direction.