A Fawlty Towers guest star reveals what it was like working on the best British sitcom of all time

"It was tremendous fun," she says. "We rehearsed for a week, as was normal, at the Acton Rehearsal Rooms – nicknamed the Acton Hilton because it looked a bit like the Hilton." Among other big shows to rehearse there were Dad's Army, Up Pompeii, The Liver Birds, The Two Ronnies and Morecambe and Wise.

"Anyway, we were rehearsing and that was enormous fun and then we got into the studio with the technicians and John said, 'Now look, we've had a week’s rehearsal. We are not going to make any mistakes. If any mistakes are made, the technicians are allowed to.' And so we were almost on pain of death not to make a mistake and we were terrified! And thank goodness – either on purpose or by accident – John made the first mistake and that broke the ice and then we relaxed a bit."

April, who was in her early thirties at the time, played Jean, an old schoolfriend of Polly's who is staying at the hotel with her boyfriend Alan, her mother and stepfather, prior to a wedding. The prudish Basil (John Cleese) leaps to a series of wrong conclusions, resulting in his complete humiliation.

Radio Times's photographer Don Smith was present at the rehearsals for most Fawlty Towers episodes, including The Wedding Party, which was recorded on 10th August 1975, in Studio TC8 of BBC Television Centre, before a live audience. "For all of us who love doing theatre anyway, it’s the audience who make it," says April.

"John was funny in rehearsals but when it came to being in front of an audience he was so over the top! He never changed the lines, he didn’t throw anybody off the script or anything... But you ask whether it was difficult not to laugh, I tell you, that was very difficult for me [laughs]. You had to be pretty damn perfect!"

The pressure is understandable when you consider that the production team had just 90 minutes to record each first-series episode – for series two they had a luxurious two hours!

In 2019, Fawlty Towers was named as the best British sitcom of all time in a Radio Times exclusive. The series topped the list, compiled by a panel of television experts, beating the likes of Father Ted, Blackadder, I'm Alan Partridge and Only Fools and Horses.

When Fawlty Towers came top, John Cleese revealed to Radio Times, “It took Connie and me six weeks to write each episode – three weeks to construct the plot and three weeks to write the dialogue. Consequently, the scripts were much longer than the usual BBC sitcoms: 140 pages instead of the standard 65 pages. This meant that we played the scenes much faster than normal in BBC TV."

There were other things going on behind the scenes at the time, as April recalls: "I didn’t realise at the beginning of rehearsals that actually John and Connie were going through a very difficult period in their marriage.

"They were writing together, they were rehearsing together. But it wasn’t until I heard John say to Connie, ‘Connie do you want a lift back after rehearsal?’ and then he’d come in the next morning and say something like, ‘Did you enjoy the show you saw last night?’ and I thought, ‘This sounds very odd to me.’ And sure enough I twigged that they were about to break up."

Despite divorcing in 1978, Cleese and Booth put aside their differences to write and star in a second series in 1979. "Nothing hindered their working relationship," adds April. "They were utterly professional."

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Fawlty Towers continues tonight (29th March) at 8.25pm on BBC One and all episodes are on BBC iPlayer – check out our full TV Guide for more.