Earlier this evening Ben Brogan, the Daily Telegraphs newly promoted Deputy Editor, Tweeted that we should expect a “fascinating poll” of Labour marginals in its northern heartland.

Though the full poll is yet to be published the Telegraph has but up al little teaser on their Telegraph View page, and reading this reveals that the poll that will be published tomorrow is indeed a fascinating. Most importantly its will be encouraging for the Conservatives.

“The YouGov opinion poll that we publish today is very encouraging for the Conservatives: it shows that the party leads Labour by 42 per cent to 36 per cent in northern marginal seats. Indeed, the Tories appear to be doing better in marginals than they are nationally: the results reveal a swing in these seats of eight per cent since the 2005 election, as opposed to 6.5 per cent nationally. But we suspect that, for David Cameron and his strategists, the most interesting statistic might be the only one that shows Labour ahead. Working-class voters in these seats favour Gordon Brown’s party by a margin of 40 to 38 per cent. In other words, Labour’s lead among its core voters in battleground seats has shrunk to only two points. That is tantalising indeed, for it suggests that Mr Cameron is close to replicating Margaret Thatcher’s greatest electoral trick: poaching the votes of people who were previously regarded as the Labour faithful.”

The Telegraph poll will cause alarm on the Labour back benchers, as it shows that all 32 northern marginal seats currently held by Labour would fall to the Conservatives if this lead can be maintained or extended.

YouGov also found that the Conservatives are regaining the trust of the northern working class voters. Among those voters in the marginals, the two parties are almost equal: Labour scores 40 per cent and the Tories 38.

According to the poll, it would appear that Brown’s attacks on the Conservative’s economic policy and his message that Labour is the only party that can fix the economy is not working as well as he hoped.

A total of 40 per cent of marginal voters think Brown’s economic policies will either make no difference or make things worse. Only 16 per cent believe Government policies have started to work.