Tancock won two bronzes at this year's World Championships

The 22-year-old touched in one minute 59.91 seconds to win the title at the National Championships in Sheffield.

"Everything I'm doing is focussed on the Olympics but a new British record is a real bonus," Tancock said.

"I'll be looking to go faster [at an international meet] in Japan and then concentrate on my Olympic preparation."

Tancock, who specialises in backstroke, claimed two bronze medals at the World Championships in April and will be aiming to go further at the Beijing Games next year.

Promising teenager Fran Hansall also took another significant step towards the Olympics as she claimed two British records at Pond's Forge.

The 17-year-old set a new national record of 54.56 seconds on her way to 100m freestyle gold.

It's more of a relief than anything that I finally have the record New British 400m freestyle record-holder David Carry

She then got back in the pool to wrap up the 50m butterfly title and British record in 26.74 seconds.

"I'm really excited," she said. "That was fast and I'm not rested for this meet. I'm hoping to go quicker."

There was also a welcome return to form for veteran Mark Foster, who took gold in the men's 50m butterfly.

On the first day of competition in Sheffield, double Commonwealth gold medallist David Carry was also in record-breaking form.

The Scot broke Paul Palmer's British 400m freestyle record, which has stood since 1988, on his way to gold.

Carry, 25, set a new mark of 3;47.40 and said afterwards: "I have been aiming for this for a few years now and it's more of a relief than anything that I finally have the record."