Just how much is your vote worth?

Candidates across Sussex are throwing everything they have into their local campaigns. But, as Parliamentary correspondent Daniel Bentley, reports, some are receiving more support than others.

All voters are equal but some are more equal than others.

In the battle for hearts and minds ahead of May 5, the main parties are targeting their resources at a minority of the population in key marginal seats.

Chief among them are the constituencies of Brighton and Hove, where reinforcements are being called in from safer seats, further afield, to fight for every last vote. It is here, rather than the True Blue shire Sussex constituencies, where the General Election will be won or lost over the next fortnight.

Campaigners for electoral reform claimed this week the results of two-thirds of Sussex seats were a "foregone conclusion".

Such is the nature of Britain's first-past-the-post electoral system only voters in the most marginal seats can hope to make a difference, the Electoral Reform Society said.

Chief executive Ken Ritchie said: "The way the first-past-the-post voting system works means parties are more interested in getting a few extra votes in marginal constituencies than getting thousands more in those that are ultra safe."

Consequently, the two main parties are believed to have identified just 800,000 people, less than two per cent of the population, who will determine the next government.

This minority holds a disproportionate influence over how much further Labour's Commons representation is diminished on May 5 or, indeed, whether it is wiped out altogether.

These are the people who are being wooed most enthusiastically by party canvassers, aware safer seats with larger majorities are less crucial to the outcome of the election.

The Electoral Reform Society listed two-thirds of Sussex seats as among the constituencies where voters have little chance of influencing the outcome.

These included Lewes, where the Liberal Democrats have a near-10,000 majority, and almost all the county's Tory seats.

The only Conservative seat in Sussex to escape the list was Eastbourne where the Lib Dems are making a concerted effort to pick off the Tories' fragile 2,154 majority.

But the real battleground for the General Election is Labour's seats in Hove, Brighton Kemp Town, Brighton Pavilion, Hastings and Rye and Crawley.

All were Labour gains in the 1997 landslide, some of them unprecedented, and all are felt to be vulnerable in the event of a Tory revival.

The extent to which they fall to the Tories, if at all, will determine whether it is Tony Blair or Michael Howard who pose for pictures outside 10 Downing Street on May 6.

Brighton Pavilion, where Labour's David Lepper is defending a 9,643 majority, is an ambitious target.

If the Tories win here, they will probably have a sizeable Commons majority.

But, if Mr Howard is to get anywhere near Downing Street, the Tories must take Brighton Kemptown (Labour majority: 4,922) and Hove (3,171). Crawley (6,770) and Hastings and Rye (4,308) are also key Tory targets.

Several thousand voters in up to 175 seats like these across the country hold the key to election victory. It is no surprise the parties are throwing their support at these seats in particular.

Nicholas Boles and Judith Symes, the Tory candidates for Hove and Brighton Kemptown respectively, have both been "twinned" with established Sussex Tories who are sitting on substantial majorities.

They have also had extra financial support from Conservative Central Office to fund their campaigns.

Mr Boles, who is enjoying the support of East Worthing and Shoreham's Tim Loughton, said: "It is the case that Hove is an absolutely key seat and the Conservative Party is throwing a huge amount of effort at it. Just as Labour is taking workers from its heartlands to put them in seats which are more touch and go, I'm getting a lot of support from safe Sussex shire seats."

Des Turner, Labour's defending candidate for Brighton Kemp Town, claimed to have seen little of his Tory opponent during the campaign. But this might simply be representative of a shift in tactics from the traditional door-knocking strategy of old.

He said: "There have been very few sightings of the Tories. They have got lots of money and they are distributing lots of glossy paper which doesn't say very much."

Both the main parties are engaged in a little-publicised telephone-canvassing campaign, designed to pick off specific voters in target seats. Computers are being employed to identify target voters in key areas, based on commercial data such as shopping and reading habits. Similar systems were used in the US Presidential elections last year.

But, for those voters who do not live in a key marginal or receive the attentions of telephone canvassers, your candidate still needs you.

Mr Boles argued that, as the differences between the main parties has narrowed, local issues have become more important and individual seats are less likely to follow the national trend.

The ultimate example of this was Wyre Forest, where independent candidate Richard Taylor overcame a massive Labour majority in 2001 after campaigning against the downgrade of a local hospital.

Mr Ritchie said: "Even if you know you have no chance of influencing who is elected in your constituency, it is still worth registering your vote to demonstrate your support for your preferred candidate."