Struggling Jackson forced to relinquish British title to rival Adlington in Sheffield

The Olympic and world medallist suffers from acute asthma which struck menacingly over the winter, restricting a 27-week training programme to just five weeks. The illness forces Jackson to breathe much harder and has caused her ribs to pop out in training.

And the 23-year-old from Northallerton was clearly in pain last night after winning the bronze medal in a race in which she is the Commonwealth record holder.

Jackson's great friend and rival Rebecca Adlington beat her to the British title, returning to the top of the medal rostrum after a fallow year in 2009 following her double-gold medal winning exploits in Beijing.

Adlington touched in 1min 57.87 seconds, more than a second ahead of third-placed Jackson, with Jazmin Carlin taking the silver.

All three qualify for the 4x200m relay at this summer's European Championships in Budapest and Commonwealth Games in Delhi.

Jackson and Adlington are scheduled to meet again in Sheffield later this week in the 800m freestyle on Thursday and the 400m on Friday.

The former may be a stretch for a struggling Jackson, but for Adlington, her return to the top step after being overshadowed by the Yorkshire swimmer at the World Championships in Rome, is a welcome relief.

Adlington said: "I'm so glad I've guaranteed my place at the Commonwealths and Europeans, it means for the rest of the week I can just relax and enjoy my swimming.

"The 800m is my favourite event and I'm always a bit unsure when it comes to sprinting in the 200m.

"I don't have as much natural speed to get up with the girls on the first turn. It's not a tactic because if I could get up to the turn as fast as they do I would.

"But it has always benefitted me building into a race."

City of Sheffield's Rebecca Turner finished seventh while a name for the future is 16-year-old Anne Bochmann, who finished third in the 200m individual medley, representing City of Leeds.

"It was slightly off my PB but I'm really pleased with that," said Bochmann who moved up to Leeds from Norwich and is still to swim her strongest event, the 400m IM, on Saturday. Middlesbrough's Aimee Willmott was second.

Rotherham's Joe Roebuck, warmed up for bigger challenges later in the week by winning bronze in the men's 200m butterfly.

Roebuck, who was pipped to the silver by Roberto Pavoni, said: "I wasn't happy with getting touched out by Pavoni at the end.

"Hopefully I'll come back stronger later in the week."