A Bristol law firm has thrown down the gauntlet to local businesses urging them to race in the 2010 Bristol 10k.

Clarke Willmott is this year's sponsor of the business challenge and is encouraging other firms to prove their strength and put a team together for the road race on Sunday, May 9.

The event, now in its third year, is helping to put Bristol firmly on the map as a running city. Entries for its sister race, the Bristol Half Marathon, have already exceeded 4,000 after opening just last week.

A number of training workshops are taking place every month from March 14 until the 13.1-mile event to help runners reach their full potential for both races.

To date more than 30 companies have entered the 10k business challenge, including Filton-based Rolls-Royce and investment firm Smith and Williamson, who have each submitted several teams.

Prizes on offer include the fastest team, highest sponsorship, fastest male and fastest female.

The challenge, open to all businesses within the region, is an attempt to encourage light-hearted competitiveness between companies and at the same time raise much-needed funds for local charities.

This year's official race charities are local organisation St Peter's Hospice and Steve Cram's charity Coco (Comrades of Children Overseas). St Peter's Hospice is also sponsoring the half marathon and looking for marshals.

One of the most scenic races in the UK, the 10k race follows the A4 along the historic floating harbour and River Avon.

Stephen Clarke, 55, a partner at Clarke Willmott, said: "We are proud to be sponsoring the run again this year. It is a wonderful way of raising money for charity and enjoying the great sights of the city at the same time. We have all experienced some tough times in the business community over the past 12 months and this seemed an ideal opportunity to bring some fun and competitiveness back into local businesses."

For more details on the Bristol 10k and the first of the workshops, which takes place on Sunday at Henbury Leisure Centre, visit www.bristolhalfmarathon.com/bristol10k.