John Barrowman has been slammed as the worst Celebrity SAS: Who Dares Wins contestant of all time as instructors on the course said they were 'disgusted' with his behaviour on the show.

The Torchwood star, 57, quit the series just 32 minutes in and he has since revealed his battle with show bosses on Channel 4 set.

He made a brief appearance on the series which began on Sunday night, and was seen vomiting before throwing in the towel.

Chief instructor Mark Billingham has since told The Mirror: 'He gave up at the first opportunity and wasted a space that another person could have taken, so it was very disappointing.

'I was absolutely disgusted, to be honest. You have a chance here to do so many great things and you just can't be bothered - he didn't even get past day one. I couldn't believe it.'

Meanwhile, instructor Chris Oliver added: 'He turned up with the wrong mindset and for the wrong reasons and wasn't willing to apply himself.

'He didn't even give it a go. He took the easy option and quit.'

Speaking about his experience on the show with Lorraine Kelly on her daytime TV programme on Monday, John told of how 'he already knows who he is' and recalled the moment bosses tried to make him stay. 

The actor explained: 'They said we would find out who we really were on the show. I thought, ''I know who I am', then I started to get sick and I just thought "I'm out".

'I couldn't have carried on if I was sick anyway.' 

He added: 'They said that we would find out who exactly we were and the show did what it was meant to do. I know who I am. I've helped people, with their sexuality. 

'It was the best decision for me, it did was it was meant to do, just in a short period of time. I would say to anyone else who is thinking about going on Celebrity SAS to just go for it.

'That lightbulb went off, the moment was when I was walking through the cafeteria, the psychologist agreed after and said "yes we could see it in your face, it changed". They tried to keep me in but I know who John Barrowman is.'

On Sunday, John shared an awkward clip of his preparations for Celebrity SAS: Who Dares Wins, before abruptly quitting the show. 

Uploading a clip of himself to Instagram from the night before filming began, he admitted at the time he'd already 'thrown up' due to his nerves.

The actor said: 'So it is the night before we start the course. I've just barfed, and I'm gonna try to get some sleep now.

'No seriously, I threw up, I think it might have been something I ate, but I feel better. Let's see how I feel in the morning, so there you go - wish me luck!'

The clip then cut to John heading into the wilderness to begin the course, after handing his valuables and briefly calling his loved ones.

He added: 'I know it's dark outside and you probably can't see, but that's me doing the walk to my valuables, I've just spoken to Scott and sent my mom and dad, everybody a message to say, send positive vibes.

'I'm super scared but, it's good to be scared isn't it?'

John captioned his post: 'Here is the video I made in bed the night before the course started on @sas_whodareswins.

'The 2nd half is the next morning walking to turn in my valuables right before we begin. I am very emotional.'

John began to vomit shortly after arriving at base camp for the first challenge. 

After the contestants put on their army uniforms the actor began heaving and declared 'I'm out'.

Asked by expert Mark Billingham if he would like to see a doctor, John said: 'No, I'm done. I just, it's not for me, I know who I am and what I'm about, it's not for me'.

As the voice over said: 'After only 32 minutes on base, number 13 John is the first recruit to leave the course.'

Viewers had little sympathy for the actor and taking to X branding him 'pathetic' and a 'diva', writing: 'Never seen anything more pathetic in my life. I bet you thought this might be a shot at redemption as well. Whoopsie!': 'Pathetic from John Barrowman': 'John Barrowman 32 minutes': 'FFS John Barrowman, I knew you were a diva, didn't think you were a huge wuss as well, certainly done yourself no favours there.

'I hope John Barrowman wasn't paid for that pathetic effort': 'Can't believe John Barrowman quits the only show that was actually willing to give him a job after just 32 minutes. What a prat'.

During the episode, John addressed the accusations that he had repeatedly exposed himself on the set of the BBC One sci-fi series Doctor Who and its sister show Torchwood.

He said: 'The press made the allegation that I was going around putting my d**k on everybody's shoulders.

'Having that happen to me ruined me, but this course is going to help me push through this and I want people to see the kind of person that I really am.'

He later added: 'On Doctor Who and Torchwood, I had to do a lot of nude scenes. If I were being stupid, I would do something stupid. 

SAS: Who Dares Wins' latest series also includes Rachel Johnson, who is the sister of former prime minister Boris Johnson, reality star Pete Wicks, former Olympic gymnast Ellie Downie, comedian Tez Ilyas, professional basketball player and Love Island star Ovie Soko and world heavyweight champion boxer Lani Daniels.

Reality TV Star Bianca Gascoigne, former England rugby captain Chris Robshaw, TV Presenter Cherry Healey, former professional boxer Anthony Ogogo, comedian Shazia Mirza, Love Island contestant Georgia Harrison, reality star Bobby Norris and former Geordie Shore star Marnie Simpson complete the line-up.

Series six of Celebrity SAS: Who Dares Wins will air on Channel 4 every Sunday and Monday from September 22, at 9pm.