Leading article: How money can distort the democratic process

Labour Party activists will be alarmed to hear not only that the Conservatives have amassed a £10m fund to fight the coming election but that they have already spent an additional £6m preparing the ground in just 117 of the constituencies which are regarded as the key swing seats. The drive has been masterminded by the party's deputy chairman, the Belize-based billionaire, Lord Ashcroft, who has bankrolled the Tories for the past three decades.

The party's opponents will protest that donations on this scale distort the democratic process. The Tories, in response, will point to the funding of the Labour Party by the trades unions. But the amounts involved are disproportionate. The Conservatives received double what Labour did in the last three months of 2009 and the governing party is going into the election at a greater financial disadvantage than any time since 1983, when it suffered a landslide defeat. The Tories are set to spend treble what Labour can afford, after cost-cutting measures that are forcing Labour to operate with about half the staff it had in 2005. But it is not simply the amounts of cash which give cause for concern. There are issues of propriety; Lord Ashcroft continues to refuse to answer the question as to whether he pays tax in Britain and whether his companies are legally eligible to make donations to a political party. There are issues of transparency too; the Tories were singled out this week by the Electoral Commission for failing to declare the money it had received on time.

Yet what should worry Labour most, though, is not Lord Ashcroft's cash but the canniness with which he has been directing the big influx of Tory money. He has not just targeted swing seats but has crunched demographic data to identify key wards and then relentlessly bombarded them with leaflets, canvassers and hundreds of billboard posters dominated by the infamously airbrushed photographs of David Cameron in an advertising blitz that Labour simply could not match. Labour and Liberal Democrat MPs with small majorities have found themselves up against weekly Tory newsletters, ads in local newspapers, telephone surveys to sound out the individual concerns of voters, followed up by targeted mailshots.

Private polling by the Conservatives shows that their lead in the polls, which has been slipping nationally in recent months, is holding up well in these target areas. The conventional wisdom is that the Tories need a 10 per cent national swing to win an overall majority. But it may be that a 6 per cent national swing would suffice, if they win more voters in these key marginals. In 2005 Lord Ashcroft bankrolled 25 of the 33 Tories who took seats from Labour and the Lib Dems. He spent so much cash that in places voters were each sent an individual DVD featuring the Tory candidate.

There is a more profound question which all this raises. The Ashcroft strategy highlights the fact that in our first-past-the-post voting system, the nation's destiny hinges on the decisions made by a comparatively tiny number of floating voters in less than one-fifth of our parliamentary constituencies. How the rest of us vote makes scarcely a difference.

Our voting system virtually disenfranchises the overwhelming majority of voters. Small wonder that so many do not even bother to turn out to vote – a figure which may well reach a new low this time. It all only serves to underscore the strength of the case for the reform of the British electoral system.