Holly Willoughby could not hide her amusement as Declan Donnelly continued to crack jokes during the opening scenes of the new series of I’m A Celebrity… Get Me Out Of Here!.

The This Morning presenter is standing in for Donnelly’s long-time co-host Ant McPartlin as he takes a continued break from his TV commitments.

She was jokingly introduced to viewers by Donnelly, who said: “Good morning, good evening, and welcome to Australia where the more eagle-eyed viewers among you would have already noticed a big change to this year’s show, yes, one of the most gorgeous presenters on British television… has been joined by Holly Willoughby!”

Willoughby said: “This is so weird. Normally about this time I’m at home, pouring myself a big glass of white wine, to watch you, and I’m in the jungle.”

Donnelly quipped: “And she’s already drunk it. And we’re ready for action.”

Donnelly, who is known for his on-screen banter with McPartlin, later delivered an innuendo-packed joke about his normal presenting partner’s absence.

Willoughby struggled to contain her laughter as Donnelly said: “It’s different, I’ll be honest – it’s a little bit different, because you know, I’ve never actually done it with a girl before.

“So, it’s a little bit different for me, I normally do it with a bloke every night, and people watching it seem to enjoy it.”

Willoughby, smirking, said: “Shall we just get on with it, maybe?”

The first four contestants seen in the show were entertainer and actor John Barrowman, ex-EastEnders star Rita Simons, The Vamps star James McVey and Coronation Street actress Sair Khan, who were met by the presenters on a yacht.

They were told they were being split into two teams – Barrowman and Khan in the red team, and Simons and McVey in the yellow team – before being whisked off in a helicopter to face the first challenge of the series.

The campmates arrived at two large towers jutting out into the jungle, and Donnelly told them: “This is The Edge – two towers heading out the side of a cliff face, 100 metres above the jungle floor.

“This is the highest challenge we’ve ever had on I’m A Celebrity. Working in your teams, you have to climb out on to the towers and collect your flags.”

Each pair had to collect 10 flags to win the challenge, in order to pick the next two celebrity contestants to join their team.

Simons and McVey won the challenge after collecting their 10 flags faster than Barrowman – who admitted he was scared of heights – and Khan.

Yellow team Simons and McVey did it in 10 minutes and 47 seconds, and red team Barrowman and Khan did it in 11 minutes and 36 seconds.

The yellow team were told they would go on to pick another two celebrity campmates to join their group.

The other stars taking part in the new series include football manager Harry Redknapp, DIY SOS host Nick Knowles and The Chase star Anne Hegerty.