By Elizabeth Hudson

Kris Kin won the 2003 Vodafone Derby at Epsom

The sponsor of the Epsom Derby is worried the dispute could harm the sport's image.

"The negative publicity this issue has generated could be a concern to us," said a Vodafone spokesman.

"We have made representations to the Jockey Club but it is a private matter between us and them."

The Jockey Club introduced a ban on riders using mobile phones in the weighing room in a bid to improve racing's integrity.

It followed a court case in which a leading former jockey admitting passing on privileged information about mounts.

But despite being granted several concessions, jockeys are furious with the restrictions and insist they need to use phones to stay in touch with agents and trainers.

A protest boycott by riders forced Sandown to abandon its meeting on Sunday. Now the dispute could be heading for court.

Mediator call in phone row

Vodafone would not be drawn on its specific concerns, but a legal wrangle over phone use would clearly not benefit a communications company.

It has sponsored the Derby since 1995 and last year signed a contract which runs until 2005.

The firm also has deals with Goodwood, including the final day of the Glorious Goodwood meeting, and Newbury racecourses.

It is estimated the company has put more than �10m into the sport since it first got involved more than a decade ago.

Vodafone's sponsorship portfolio also includes the Ferrari Formula One motor racing team, Manchester United and the England cricket team.