Left-winger Mr Leonard reiterated his disappointment in his predecessor’s decision to skip Holyrood for three weeks without permission amid an ongoing row over her involvement in the ITV show.

The Lothians list MSP has faced a backlash from both political colleagues and constituents after jetting off to the Australian jungle while the Scottish Parliament is in session.

Ms Dugdale has defended the move describing the contest as “an amazing opportunity to talk to young people who watch this programme about politics, and in particular, Labour values.”

But Mr Leonard, an ally of Jeremy Corbyn, said: “I realise that it’s a very popular programme, which is seen by millions of people, I think it’s got the highest viewer ratings over the course of the last week, I’m not down playing the reach that the programme has, I’m not sure the circumstances in which it presents politicians is the one that certainly I would choose, and I’m not sure it’s a good way of getting across the message of socialism on television.”

Ms Dugdale, who dramatically quit as leader in August after two years at the helm, made her debut on show on Thursday night when she failed in a political-themed team trial.

She has escaped immediate suspension from Scottish Labour over her “unauthorised absence” but faces the threat of disciplinary action when she returns.

Ms Dugdale has said she delayed her arrival on the show in an effort to avoid clashing with last weekend’s Scottish Labour leadership announcement.

But the news leaked out last Friday before she flew out to start filming on location.

The 36-year-old plans to donate the pay she will earn as an MSP while in Australia to the homelessness charity The Rock Trust.

She has also pledged to hand over part of her fee for appearing on the show.

But in an interview with ITV’s Good Morning Britain, Mr Leonard made clear he was not happy with her participation.

He said: “I was disappointed that she chose to do that.

“There are two things: one is we expect our MSP’s to be diligent in their parliamentary work.

“It’s a great privilege and honour to be elected by the people to be their representative in parliament.

“Second, there is an issue about the fact that she sought authorisation and didn’t get it.

“She’s there on unauthorised absence.

“So that’s a bit of an issue for us inside the Labour Party in Scotland.”

Asked if she will be fired, he said: “No, when she comes back in three weeks time from Australia the group manager will sit down and have a discussion with her and having heard her view, got her side of the story, will then take a decision based upon that.”

A spokesman for Ms Dugdale said: “Kez hasn’t been able to personally congratulate Richard on his victory, but sends him her very best wishes.

“Kez hopes her Labour values will shine through while she is in the jungle, and it will demonstrate that politicians are human beings.

"Appearing on the show will also offer other opportunities for her to promote Labour policy when she leaves the camp.

“But her main focus will be returning to work as Labour MSP for the Lothians, a job she fully intends to do for the long-term.”