Claire Hallissey is facing two big races against the clock on Sunday.

The first is the Bristol half marathon at 9.30am, when the 26-year-old Bristol & West AC runner will attempt to win a place in the Great Britain team for the World Championships next month.

If Hallissey's race goes according to plan, she should reach the finishing line not long after 10.40am, take her plaudits for a terrific run, fulfil her media duties and then rush off to shower and change for her next race against the clock.

"I have a 5pm flight to catch to Washington that day and I'm looking to get the coach at 12.30pm to get to Heathrow in time," said Hallissey.

"I am basing myself at the University (where she works as a post-graduate student) because it is closer to the race than home and I'll be rushing there after the race for a shower and change and then straight down to the bus station.

"I don't want to miss the bus or plane as I'm off to see my husband Matt, who has been working in Washington since July. I haven't seen him since he left so it should make me run quickly."

Not that the ultra professional Hallissey needs any extra incentives to perform well in tomorrow's race.

Bitterly disappointed at missing the 2008 race through injury, Hallissey has since emerged as one of Britain's best long distance runners, making her GB debut on the track at the European Cup 10,000m Championships and improving her PB to 33mins 10.73secs to rank second in the UK.

She also recently won the Newark-on-Trent half-marathon in a personal best time of 73mins 17secs to go fourth in the UK rankings behind Mara Yamauchi (68:29), Paula Radcliffe (69:45) and Michelle Ross-Cope (72:35).

The first two will not be in Bristol, though are likely to get a place in the Worlds if they wish, but Ross-Cope, who ran in the Worlds last year in Rio, is entered as are Bath's Holly Rush, in-form British international Gemma Miles, British cross-country international Hattie Dean, Winchester's Jo Meek (nee Kelsey) and Bedford's Jo Wilkinson, who finished in third place in the London Marathon earlier this year.

"I am very excited about Sunday's race," added Hallissey.

"It is all about running for a place rather than a time and I know that if I run well enough to win a place in the Great Britain team for Birmingham then I will have had to run a quick time.

"I'm just going to concentrate on getting a good position and let the times come along but it will be nice to run with some other good women. It should be a terrific race."

The first two British women are guaranteed a place in the team, so Hallissey knows what she has to do. And she does not want to miss that plane.

Westbury Harriers have a strong women's squad spearheaded by Robyn Golding, who is seeking to break 1hr 25mins, Sophie Voller, Emma D'Alton, Debbie Cleary, Lizzie Smith and Catherine Dulla.

In the men's race, the local challenge is likely to be led by Bristol & West AC's Tom Merson, who will be seeking his third personal best performance in a week after winning the Battle of Sedgemoor 10k (31:15) last Sunday and clocking 15:02 for second place in the Run Exe Summer 5k on Tuesday.

Phil Parry, Steve McGuigan and Haggai Chepkwony will complete the Bristol & West AC team, while the likes of Bitton Road runners, Clevedon AC, Great Western Runners and Westbury will also have a big presence.

World Championships marathon runner Tomas Abyu will be among the British frontrunners along with the 2008 Bristol champion Tom Payn, who clocked a PB of 65mins 00secs for third in this year's Bath event.