Katherine Grainger could miss out on the Rio Olympics after it emerged that she and Vicky Thornley have failed to force their way into the women's eight boat.

Sportsmail can reveal that Grainger, who is aiming for a record fifth Games, and Thornley, one of the sport's outstanding athletes, both fell agonisingly short in a race-off against existing members of the women's eight. Each missed the cut by less than half a second.

Their double sculls boat was disbanded last month after they underperformed at the European Championships and although they may still be selected in a reformed double or as reserves their medal chances in Rio this summer are fading.

Katherine Grainger (left) and Vicky Thornley are set to miss out on a place at the Olympic Games in Rio

Grainger, left, and Thornley wanted to be included in the women's eight after their double sculls was disbanded

Grainger has won three Olympic silver medals in addition to the gold which she claimed at London 2012

Grainger, who is the joint most successful British female Olympian in history, won gold in the double sculls at London 2012 after three consecutive silver medals. Thornley won a bronze medal in the women's eight at the World Championships in 2011 and finished fifth in the same boat at London 2012.

She is widely considered to be one of the most talented rowers in the Great Britain team, winning the single sculls at the Olympic trials last month by more than seven seconds.

Thornley's boyfriend Rick Egington, who won Olympic silver in 2008 and a bronze at London 2012 with the men's eight, claimed the women's team has been mismanaged by chief coach Paul Thompson.

'I rowed under the men's head coach Jurgen Grobler for 10 years and he was very hard but always fair,' said Egington.

'With Paul, I think he has to be accountable for what he's been doing in terms of causing unnecessary stress to his top athlete.

'You should always feel like your coach has got your back but from what I've seen Vicky often hasn't been treated in the way a top athlete should by Paul. When she's raised concerns I feel he has been overbearing and undermined her performances.'

Thornley, a former showjumper, moved into rowing in 2008 and came fifth in the women's eight at London 2012

Thornley's boyfriend and Olympic medallist, Rick Egington, suggested the team has been mismanaged

Egington said he felt women's chief coach Paul Thompson had undermined Thornley's performances

Egington claimed that senior rowing figures expressed doubt when Thompson allowed Anna Watkins, who won gold with Grainger at London 2012, to come straight back into the elite set-up after three years out, during which time she had two children.

As a storyline the idea of Watkins and Grainger reforming to defend the title they won in one of the most enduring moments at London 2012 was irresistible. Watkins was then pitted against Thornley, 28, and Grainger, 40, for two seats in the double but she was pulled out of the programme in February after tests revealed she was not at the right level.

'Bringing someone back who had three years away from the sport and putting them straight back into contention is the most ridiculous idea in the world and it put undue stress on Vicky,' claimed Egington.

'When you read about it, it seems like a brilliant story but this is real life and high performance sport and to bring someone back in, fantastic athlete though Anna was, just 10 months away from the Olympics was not the right thing to do.'

At 6ft 4in, Thornley, a former model and showjumper, found rowing after being spotted by the Sporting Giants project set up by UK Sport in 2008 with a view to mounting the strongest assault on the medals at London 2012. She swapped her job as a barmaid for elite sport but is now left feeling very concerned about her prospects of going to another Olympics.

Egington (left) pictured in action with the men's eight prior to the Olympic repechages during London 2012

Talks are still ongoing about whether she and Grainger, who came out of retirement in 2014 after two years away from the sport, will be selected to go in the double sculls boat which is already qualified for the Olympics and it is not known if they would take British Rowing up on the offer.

British Rowing said in a statement: 'Selection in sport is always an emotive issue and never more emotive than in Olympic year. Coaches have to make hard decisions.

'British Rowing is confident that the process that we have followed for both Vicky Thornley and Katherine Grainger has been appropriate.

'They were clearly disappointed with their performance in the women's double scull at the European Championships in early May.

'Whilst we had not lost confidence in them and felt they were still a potential medal boat they asked to be considered instead for selection to the women's eight, which is already a proven medal winning combination.

'We opened up a process and gave them the opportunity. They have not been successful and we are now looking at next steps in a selection process which is ongoing.'