The Tories, still smarting from losing seats in the Bradford district in the last General Election, have made the constituencies, particularly Shipley, key electoral battlegrounds. Colin Mellors, professor of political science at the University of Bradford gives an expert view of the likely outcome when the country goes to the polls on June 7. In 1997, Labour made several local gains - Shipley, Leeds North West, Calder Valley, Pudsey, Batley and Spen, and Keighley - all now obvious Conservative targets.

The task facing William Hague is formidable. He needs a 7.2 per cent swing simply to remove Blair's majority and 9.9 per cent to make the Conservatives the largest party. Outright majority requires a massive 11.5 per cent swing from Labour.

Considering that their best performance in the last 50 years was Mrs Thatcher's 5.2 per swing in 1979, the task looks near impossible. Further gloom comes from Labour's steady 20 per cent lead in the opinion polls. Indeed, as things stand, there would be further Conservative losses (including an additional Yorkshire seat) rather than a fight back.

However, when it came to real votes in the 1999 European Elections and last year's local elections, Labour supporters stayed at home in large numbers and, for the first time since 1997, Conservatives came out on top.

The fear for Tony Blair is that the same will happen on June 7 and significantly reduce his current lead.

Of Labour's 1997 gains, Shipley is the most marginal in the whole of Yorkshire and Humberside. Chris Leslie will need to fight hard to hold off the challenge from David Senior. The Conservatives need a mere 2.8 per cent swing to win.

Next most vulnerable are Leeds North West (3.9 per cent swing required), Calder Valley (5.5 per cent swing), Pudsey (5.9 per cent), and Batley and Spen (6.5 per cent) where Elizabeth Peacock is hoping to regain her former seat. Labour could afford to lose all of these and still retain an overall majority at Westminster.

Keighley - often a benchmark seat - needs a 6.9 per cent swing to change hands. If Ann Cryer was to lose then Tony Blair's majority would start to look shaky.

Bradford West will also be watched closely. Mohammed Riaz is again fighting for the seat won by Marsha Singh in 1997 and needs a swing of 4.3 per cent. Like Shipley, the seat would have gone to the Conservatives at the last three local elections and, significantly, was one of only two seats nationally that resisted the national tide in 1997 and saw a swing towards the Conservatives.

The battle lines are already drawn. Labour wants to reassure voters that it can improve public services but not increase taxes, while Conservatives are intent on showing they can cut taxes without threatening services.

But with the polls suggesting considerable disinterest, especially among the young, perhaps the biggest challenge to all parties will be persuading voters to turn out on June 7.

l Health Secretary Alan Milburn was due to tour the Windhill Green Medical Centre in Shipley today with Labour's Chris Leslie. Then he was expected to meet Batley and Spen Labour candidate Mike Wood for an insight into the work of West Yorkshire Ambulance Service at its headquarters at Birkenshaw, Bradford.