Perri Shakes-Drayton believes her growing rivalry with Eilidh Child can spur both Britons into the Olympic 400 metres hurdles final.

The pair go head-to-head again tonight at the Diamond League meeting at Crystal Palace, three weeks after Shakes-Drayton overhauled the Scot to win the UK Championships in Birmingham.

The race, potentially their final chance of preparation ahead of the Games, pits both against a field that includes Jamaica's Kaliese Spencer, as well as European champion Irina Davydova.

However, the battle for supremacy within the British squad provides an extra incentive for Shakes-Drayton.

"You need that rivalry because athletes tend to become too complacent if it's too easy," she said. "I knew it wouldn't be easy at the trials with Eilidh in the race and that's what we need. We're pushing each other. We both want to beat each other and that's good."

The pair might also be team-mates for GB in the 4x400 metres relay in London but after both missed out on last year's world championship final, Shakes-Drayton admits the target for her and Child must be the Olympic hurdles finale.

"There's a few athletes out there capable of doing it but it would be great if we both did it for Great Britain," she said. "It's good to see both of us running world-class times."

Eilish McColgan, who struggled in a low-key 1500m earlier this week, has opted out of the 3000m steeplechase in the London meeting in favour of the 5000m, while Lynsey Sharp will not run in the 800m avoiding a controversial meeting with Marilyn Okoro. The European silver medallist will instead run for Scotland in a 400m relay next week in Cardiff.

"There was an option of competing in the Diamond League in Monaco on July 20 instead of Crystal Palace but after talking to my coach we felt this was the best schedule for me," said Sharp. "Scotland women had a great 4x400m relay effort when winning at the Loughborough International and everyone is involved except Eilidh Child."