Jules Knight has admitted he was ‘slightly on edge’ when he learned he would have to kiss his Agatha Raisin co-star Ashley Jensen.

Jules – best known as Holby City‘s Dr Harry Tressler – guest stars in next week’s episode of Sky1’s comedy crime drama as Guy Freemont, the charismatic owner of Ancombe Water, a firm hoping to make a fortune from bottling water from a Cotswold village spring.

In need of some positive publicity, Guy enlists the services of PR guru-turned-amateur sleuth Agatha, played by Ashley.

Talking to What’s on TV about the role, Jules said: “Agatha’s brought on to help Guy with PR because we have a bit of a PR disaster for various reasons and Agatha comes in to help with that.”

He added: “It’s interesting to see how that character develops and how his relationship with Agatha develops throughout the episode.”

Indeed, Jules’ role meant he had to passionately kiss co-star Ashley Jensen (Agatha) several times.

“I remember reading the script and going: ‘Oh, they kiss’… ‘they kiss again’… ‘Oh wow, there’s a lot of kissing,’” said Jules. “I felt slightly on edge when I read that we were kissing all the time. I’m a big fan of Ashley, so it was a little bit scary, but she put me completely at ease and luckily we got on very well and became good friends.”

Jules described Agatha Raisin as ‘the most enjoyable job I’ve done’, and it seems there was lots of fun to be had on set.

“My only challenge was trying to keep a straight face when I was filming with Mathew Horne (Roy Silver),” he said. ‘Stuff just comes out of his head and he does these things that you just don’t expect. I’m the guy having to keep a straight face, so that was the biggest challenge.”

Agatha Raisin continues Tuesdays at 9pm on Sky1.