BRITISH SWIMMING CHAMPIONSHIPS
Venue: Pond's Forge, Sheffield
Date: Monday, 31 March to Sunday, 6 April
Coverage: BBC Sport website & BBC Radio 5 Live Sports Extra from 0955 BST
Marshall is a medal hope for Great Britain in Beijing
Medal hopeful Mel Marshall will not be able to race in two Olympic events after a mix-up at the British trials.
Marshall was ruled out of the 100m freestyle and 100m relay team after failing to turn up in time for the 100m final at the British Championships.
"I was five minutes late, it's my own responsibility," the ex-British record holder told BBC Radio Lincolnshire.
"I was standing outside the [pre-race meeting] room, but when I went in they said they had called the reserve."
Swimmers are required to gather in the pre-race call room before their race and BBC Radio 5 Live correspondent Bob Ballard said the rules were always strictly observed.
He also confirmed that the 26-year-old Marshall had decided not to appeal against the decision.
"Swimmers have to report to the ready room 15 minutes before their swim. Mel Marshall did not, and so by the rules she's not entitled to race," he said.
"She wasn't happy about it, but there's no bending the rules, despite the fact this is Olympic qualification.
"So she can't do the 100m freestyle in Beijing or indeed as it stands at the moment be part of the relay team for the 4x100m.
"The 100m freestyle is a strong event for her, but arguably the 200m freestyle is her stronger event so she will hopefully be part of the 4x200m team later on in the week.
"The 4x100 team did have an outside chance of a medal in Beijing, but I don't think they've got one any more."
You're supposed to be a professional athlete and if you can't get to the call room on time then everybody knows the rules
Her coach, Ian Turner, had little sympathy, saying: "Mel should have been in that call room, she should have reported, but she didn't and suffered the consequences."
Scotland's Caitlin McClatchey overhauled Fran Halsall in the final metres to win the final in a time of 54.58 and book her place at the Olympics.
Halsall, who lost her British record to McClatchey in Monday's heats, also clinched her place in the team for Beijing by coming second in 54.81.
Speaking about Marshall's disqualification, 17-year-old Halsall said: "If you're not there you're not there, it's your own fault.
"You're supposed to be a professional athlete and if you can't get to the call room on time then everybody knows the rules."
Gregor Tait, David Carry, Dean Milwain, Jemma Lowe and Ellen Gandy also secured their tickets to China, although all the swimmers must still be nominated for official selection by the British Olympic Association.
I was a bit nervous for this morning and I bet there is no-one else in the world who can say they went to bed at 9pm on their 18th birthday
Tait edged out his rivals to claim the 100m backstroke in a personal best 54.22 - and with it the final spot in the discipline after Liam Tancock clinched his Olympic berth at last year's World Championships.
Carry triumphed in the 400m freestyle from Milwain while Lowe won the 200m butterfly from 16-year-old Gandy.
Lowe, who broke the British record in the heats on her 18th birthday on Monday, is now a medal contender in Beijing after her efforts promoted her to second fastest in the world this year.
"I was a bit nervous for this morning and I bet there is no-one else in the world who can say they went to bed at 9pm on their 18th birthday," said Lowe.
"But it doesn't matter - I got the British record - and now I'm going to Beijing."
Swimmers have to achieve the Olympic qualifying time set by British Swimming in the heats and then need to finish in the top two in the final for selection.
In order to replicate the programme in Beijing, heats are swum in the evening with the finals the following morning.