Welcome to the General Election 2010, where David Cameron hopes to break more than a decade of Labour rule. John Hipwood assesses his chances.

Rather surprisingly, Tony Blair turned up on the campaign trail last week to lend his support to his party’s and Gordon Brown’s bid to win a fourth general election for Labour.

It was 13 long years ago when a fresh faced Tony Blair was wowing the voting public and the nation was mouthing the words to D:ream’s ‘Things Can Only Get Better’.

That dream has long been shattered, and D:ream are better known today for keyboard player – Professor Brian Cox’s magnificent BBC TV series, Seven Wonders of the Solar System.

In 1997 the nation was convinced that things under New Labour and its young, dynamic leader would get better had to be better than the sleazy disarray of the faltering John Major administration.

Hope abounded. During the election campaign I tramped the streets of Whitmore Reans with Nick Budgen, who had represented Wolverhampton South West for 23 years. Surely he would be returned to Westminster again. Well, the disarmingly honest lawyer/farmer wasn’t so sure, and when I looked in on Jenny Jones’s campaign, there was plenty of support for her on the doorsteps.Mrs Jones was duly elected.

Just up the A41 in the traditionally swing seat of The Wrekin, Labour had mobilised so many young people to campaign for Peter Bradley that the mood for change was there for all to see.

The creation of the new constituency of Telford meant Mr Bradley had to overturn a notional Tory majority of 16 per cent. Conservative candidate Peter Bruinvels should have been safe among the pleasant streets of Newport and Shifnal and the surrounding villages. He wasn’t. Tony Blair ended up with a 43 per cent share of the vote and a 179 Commons majority.

The swing to Labour had been over 10 per cent on a 71 per cent turnout. Conservative Chancellor Kenneth Clarke’s tough measures had helped the country out of the early 90s recession, but the chaos and humiliation of Black Wednesday when the UK was forced out of the European exchange rate mechanism was still clear in people’s minds.

For all that John Major was more popular than his party, throw in the sleaze and continuing arguments over Europe and you couldn’t avoid the mess the Tories were in, and they crashed to their worst defeat since 1906.So are we in for a repeat performance next month, with another young, fresh-faced Opposition leader, David Cameron, riding the white charger to our rescue?Well it’s anybody’s guess.

Less than two years ago, the Conservatives enjoyed a lead of 26 points in a YouGov opinion poll. This month, their lead is down to single figures. And the size of David Cameron’s task is enormous. If Mr Blair managed to climb Mont Blanc, the Tory leader has to reach the summit of Mnt Everest. The bald statistics show us that the Conservatives need to make a net gain of 117 seats on May 6 and achieve a swing of at least 7.5 per cent to have a clear majority in the new parliament.

The latter has been achieved only once since the Second World War in 1997.

What’s more, it’s perhaps surprising that Mr Cameron’s party has only once defeated an incumbent non-coalition government with a working Commons majority since the end of the 19th century 40 years ago when Edward Heath won against an over-confident Harold Wilson.

Much has been made of the millions of pounds that Lord Ashcroft, the tax-controversial Tory vice-chairman, has pumped into marginal seats – the 100 or so that will decide the election. But Labour, helped by cash from the Unite union, and the Liberal Democrats have also been concentrating their efforts on the marginals they are defending.

And there is clear evidence Messrs Cameron and Osborne are not viewed as favourably in the Midlands and the North, where many of the marginals are to be found, as they are in the South.

What no poll and no one has been able to quantify is the impact of the expenses scandal.Although not altogether untainted, the Lib Dems will probably come off lightest if only because they had fewer MPs to fiddle the system. So voters might well think on May 6 “a plague on both your houses” and it will be Labour and Tory candidates who suffer most.But what we don’t know is what those unhappy voters will do if they do turn their backs on the two biggest parties.

Will they switch their votes to the Lib Dems, or UKIP or even the BNP, or will they simply stay at home?As we start the official election campaign, the Tories are still stuck at base camp in that attempt to climb Everest, and now there are only 30 days to go to reach the summit.