The ‘class clown’ from the racy BBC sitcom discusses his return to the stage, the draw of the dark side and preparing his parents to see him in ‘full bum’ nudity on screen

For the past five weeks, Joshua McGuire has been in a whitewashed room in north London pretending to be a rhinoceros. The 37-year-old actor isn’t in a performance art piece or strange social experiment, but rather starring in director Omar Elerian’s new production of Eugene Ionèsco’s 1959 absurdist play, Rhinoceros; it is his first stage role in seven years. “It sounds mental but it’s the theatre of the absurd, so it’s meant to be baffling at points,” he says with a smile, back in human form in a white T-shirt and cap while on a break from rehearsals, where he is clearly enjoying taking on the story of a small French town whose inhabitants gradually turn into rhinos.

If you have watched a British comedy over the past decade, it’s likely you’ve seen McGuire in it. The endlessly energetic performer is usually found next to the leading man, sporting a frizz of curly hair and delivering anxious one-liners or slapstick pratfalls. He has featured in everything from Netflix series Lovesick to Richard Curtis’s About Time and Emerald Fennell’s Saltburn. On stage, meanwhile, he had his breakthrough in Laura Wade’s 2010 satire on the British upper classes, Posh, playing a member of a fictionalised version of the Bullingdon Club, and has since starred opposite Daniel Radcliffe in David Leveaux’s 50th anniversary production of Rosencrantz and Guildenstern Are Dead.