Zara Phillips has two rides at this week's Badminton Horse Trials as the British equestrian team look to finalise their Olympics squad.

Reigning world champion Phillips will board Glenbuck and Ardfield Magic Star at the world's largest three-day event.

Mary King, who, like Phillips, is regarded as a certainty to represent Britain at the Olympics, rides Imperial Cavalier and Apache Sauce.

The likes of Pippa Funnell will compete for the other three Games places.

The veteran took team silver and individual bronze four years ago in Athens, but may need a good result at Badminton to make the final team and teams up with Ensign, a horse that has yet to make a real mark at Championship level.

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Fellow veteran William Fox-Pitt leaves his main Games hope, Parkmore Ed, at home but will have two other contenders for the top prize.

Elsewhere, Daisy Dick was part of the team that won European Gold last year and she teams up at Badminton with her main Olympic horse, Spring Along, while the other member of last year's victorious team, Oliver Townend, is hoping to line up this week despite having been battling with injury since breaking his collar bone a fortnight ago.

Lucy Wiegersma has been impressing many shrewd judges on Shaabrak and, lastly, Tina Cook rests her main hope Miners Frolic but combines duty in the BBC commentary box with guiding First Flight through the three days of competition.

Phillips, whose main ride Toytown will not be at Badminton, will be looking to complete the event for the first time after withdrawing before the cross country last year.

Riders have reportedly taken advice from the selectors and weighed up whether they have done enough already to make the British Olympic team or whether they must take the last big chance to secure selection for the Games, which will take place in Hong Kong.