Cassani bans fast-food and soft drink sponsors from London's £30m bid for the Olympics

Fund-raisers for London's bid to stage the 2012 Olympic Games are to ban fast-food and soft drinks companies from becoming sponsors.

The companies will join a blacklist including political organisations, arms manufacturers and tobacco companies that will be prevented from using the bid for promotion in return for a donation.

Barbara Cassani, the chairman of the bid team, hopes to raise a third of the £30m cost of the bid from the private sector, but fears that donations from fast-food companies may undermine the message that the games can deliver health benefits by motivating young people to take up sport.

The move, which has been welcomed by health campaigners, is likely to be supported by the Government - the bid's main financial backer - which is tryingto cut child obesity. The Food Standards Agency (FSA) has embarked on a consultation on the promotion of foods to children, which is likely to result in restrictions on advertisements directed at children. The bid company has been targeting London-based companies from the financial, retail and telecommunications and construction sectors. It has also accepted donations in cash or kind from the Post Office, City law firms and the Canary Wharf Group. Commercial deals are regulated by the International Olympic Committee which would take a dim view of London accepting sponsorship from direct rivals to its 11 global sponsors that include Coca-Cola and McDonald's.

A source from the bid company said: "Considering the Government's health agenda, it would be seen as politic to turn down donations from companies producing food or drink we consider inappropriate. If we have 95 per cent of our private sector kitty full then we would have to think seriously about accepting anything from a crisp manufacturer, for example, for the remainder of our funds."

Kath Dalmeny, a policy officer for the campaign group, the Food Commission, said: "The Olympics is meant to be an aspirational event intended to get people interested in sport. This message is completely undermined by the choice of sponsors sometimes."

A spokesman for the FSA said: "The consultation will look at the promotion of unhealthy foods in schools, on television and by celebrities so this is relevant to how the Olympics is marketed."

The bid will take on a higher profile next month with a poster campaign designed by M & C Saatchi, appointed last week to develop marketing and advertising. The bid's marketing director, David Magliano, has negotiated advertising space on billboards, public transport in London and black cabs.

The electronics retailer Dixons is close to an agreement to display a "London 2012" poster featuring the "squiggly" logo in scores of its high street stores around the country.