Gareth Warburton, Richard Kilty and Jemma Simpson are amongst the athletes hoping to win appeals against their Olympics omissions on Friday.
The trio found out they had missed out on the 77-strong Team GB athletics squad when it was announced on Tuesday.
Welsh 800 metre runner Warburton achieved the required 'A' standard time for London 2012 this season, although he failed to do so at last week's European Championships.
Warburton was seeking a place alongside Andrew Osagie and Michael Rimmer, but was overlooked and on Thursday confirmed his appeal.
He posted on Twitter: "Officially appealed against my Olympic omission. Waiting to hear back tomorrow or Saturday on the panels decision."
Kilty has also announced his intention to appeal having hoped to be selected in the 200m, while the women's 800m is proving a big talking point.
Jenny Meadows has announced she will not fight her omission, although fellow 800m hopeful Simpson has confirmed her appeal.
Simpson - along with Meadows, Marilyn Okoro and Emma Jackson - was left out the squad despite possessing the 'A' standard, unlike the selected Lynsey Sharp.
"I think there is grounds for all four girls that haven't been picked for the team to appeal," Simpson told BBC Cornwall.
"I've sent my letter and I hope everyone else does too.
"Four athletes have been sacrificed for one. One showed current form and the selection process is so extensive you could have picked any one of the four, I don't know how they came to their decision - I think it's the wrong decision.
"Lynsey deserves a place. In a home Games when there's an option for three places you have to fill the spots, [so the team has] three chances to get to the final.
"The British public like to see a full team out there - it is in the spirit of the Games."
Any appeal had to be lodged within 24 hours of the team announcement and then heard within 48 hours.
The appeals panel consists of UK Athletics (UKA) chairman Ed Warner, UKA president Lynn Davies and an independent barrister.
However, such appeals would seem likely to fail given that they can only be based on whether facts have been overlooked or the selection panel has not adhered to their published policy.
