With the average runner raising pounds 300 in sponsorship money, and some making upwards of pounds 10,000, charities are prepared to go to great lengths to woo those taking part in the race.
In literature circulated to the 30,000 competitors, the Get Kids Going charity for disabled children boasts: "Try Beating This For An Incentive" as it offers all its runners a guaranteed free champagne flight on Concorde, with the top fundraiser winning a free holiday in Barbados.
Age Concern tempts runners with the chance to fly anywhere in the United States, while the British Heart Foundation guarantees its top fundraisers a place in the New York City marathon.
Other charities directly link prizes to the amount raised by the runner. Muscular Dystrophy will give a free mountain bike or sports camera to those raising more than pounds 1,000, with free running shoes for competitors generating pounds 500 or more. The Royal National Institute for the Deaf offers a free CD player for those who raise pounds 1,000 and a trip to Paris on Eurostar for the top fundraiser.
But some of the poorer charities are being left behind. Shelter, the charity for the homeless, tells competitors: "No holidays to South America, no free weekend at a health spa, no colour TV ... but what we can offer is hope."
Fiona Head, the charity's fundraising officer, said: "It has become very competitive because we are all trying to get a slice of the cake. We can't afford to offer major prizes and it's going to be very difficult for some of the smaller charities to keep up." Headway, the charity for people with head injuries, admitted: "It's hard for us to compete because we just haven't got the resources."
The competition has been made even more intense this year by the presence of the Diana, Princess of Wales, Memorial Fund, which is hoping to field a team of 1,000 runners. The Diana fund and Age Concern are the official charities for the 1998 marathon.
Some charities are using celebrity supporters to persuade marathon runners to join their cause.
Steve Cram is hosting the Macmillan Cancer Relief post-race pasta party, while Daley Thompson is backing Barnardos, and Sebastian Coe is supporting the Royal National Institute for the Blind. Former marathon winner Liz McColgan backs the Starlight children's charity.
Meanwhile Scope, which gives its runners the chance of winning a year's free membership of a health spa, also offers them a pair of running shoes signed by the star athlete Denise Lewis.
Stephen Lee, director of the Institute for Charity Fundraising Managers, said charities must be careful to remain within the law. "If a charity is paying for inducements it may be engaging in trading activities rather than fundraising activities, which is against the law for a charity," he said.
Mr Lee pointed out that the fierce competition was indicative of how important the marathon had become to charities.
"Last year the marathon raised some pounds 11m for charity. It is a very significant event and is up there with Children in Need and Comic Relief in its importance to this sector," he said.
Nick Bitel, chief executive of the London Marathon, said: "This year we confidently expect to raise more than pounds 14m which is more than any other one-day event.
"The prizes that are offered help to incentivise fundraising but I don't think they make people switch from one charity to another. The best fundraisers per head are usually running for some of the smallest charities."
Some 80 per cent of British runners in the marathon will be raising money for charity. In most foreign marathons, the charity fundraisers number only a handful.
"The charity work and the fancy dress is a very British thing," said Mr Bitel. "It makes the London Marathon this strange mix of wonderful sporting event and great community occasion at the same time."
The marathon organisers have given all runners special advice on how to maximise the effectiveness of their fund- raising. Competitors are advised to write up a press release about themselves and send it to media outlets.
Those working in business are told to "focus on board rooms and managers with access to budgets".
Charities pay pounds 235 to the marathon organisers for each place they are given under the Golden Bond scheme, which reserves around 3,000 places for them.
The charities usually ask runners who contact them for a place to guarantee a sponsorship donation of, typically, pounds 1,000.Reuse content