She is the most memorable villainess in cartoon history – Cruella De Vil, the sneering, fur-draped epitome of vanity, greed, and animal cruelty. Now, creepy Cruella is being brought to life in the 101 Dalmatians musical by 2024 Britain’s Got Talent winner Sydnie Christmas. And Jeff Brazier, a regular face on British TV for 24 years, has just made his stage debut alongside her. “I have never slept better,” Jeff, 46, chuckles when I catch up with him and co-star Aston Merrygold during a break in rehearsals. “I come home every night mentally knackered. The fear of not being ready means you do extra work when you get home and when you’re commuting. You’re on the Central line, smelling people’s armpits, holding the script in one hand, just trying to go over it…”

The likeable pair play Cruella’s bungling sidekicks, Casper and Jasper, tasked with stealing and killing puppies to make her fur coats. How do you get into that despicable mindset? “To be fair, the characters haven’t got much of a mind,” laughs Jeff. The two first met 17 years ago, when Jeff hosted The X Factor Live Tour, featuring Aston’s chart-busting boyband JLS. “Aston is so on top of his choreography, words and lyrics, he makes it seem like he knew them before he even turned up at rehearsals,” says Jeff. “He’s the perfect person to play alongside.”

And that’s despite that unbridgeable gulf between you? I tease – Brazier famously supports Arsenal, while Merrygold is Tottenham Hotspur through and through. “We haven’t discussed that,” Jeff grins. “The show hasn’t opened yet, Garry,” protests Aston. “Don’t open up that argument.” “What argument? One team is clearly superior,” says Jeff, whose cherished Gunners finished second in the Premier League, while Spurs narrowly escaped relegation, before scooping the Europa cup. Both played football in their teens. Berkshire-born, Essex-raised Brazier had a promising youth career with West Ham United and was a defender for Leyton Orient; Peterborough-born Merrygold played for England in the European Youth Games. “We were both pretty handy,” Aston, 37, says. But injuries scuppered their soccer careers, so now they’re tackling different challenges. How’s Jeff doing? “He’s earned his stripes,” says Aston. “To come into a theatre with a director throwing curveballs at you, you have to maintain composure and apply those notes properly pretty much straight away. You haven’t got all day to focus on a two-page scene. You’ve got 15 minutes at best. They’ve thrown so many curveballs at us…Massive kudos to Jeff for staying on top of it. His attitude is: ‘Let’s crack on, son!’.

“And Sydnie is brilliant, she is so, so good,” he adds, with puppyish enthusiasm. “We can get lost in the script just watching her.” Jeff: “Her costume takes everything up ten-fold. She’s a whirlwind of energy. She’s always performing. Even when we’re just standing around, she brings so much energy to the table.” Not that the cast get much chance to stand anywhere for long. The show opened on July 18, shortly after our chat. Merrygold is a musical theatre veteran who sparkled in Footloose, Rip It Up and The Wizard Of Oz (playing The Tin Man). His Jamaican father and Northern Irish mother split when he was young. He started doing extra work in children’s TV when he was about 14 and landed his first proper role at 15 on CITV’s Fun Song Factory. A year later, he moved to London doing any job available – pot washing, table service, cold-calling – as he strove to make it in entertainment. Aston’s TV work ranges from a 2002 Stars In Their Eyes (as Michael Jackson) to CBBC comedy drama Almost Never, via The Masked Singer as “Robin” – beaten by Josh Stone’s sizzling Sausage. Last month he made his voice-acting debut in Disney’s Elio. Aston’s big break came in 2008 when JLS came second on The X Factor behind Alexandra Burke. The quartet notched up five No 1 singles, seven more Top 20s, and five hit albums, three of them platinum. They split in 2013, returning for a 2021 reunion tour with another one lined up for Autumn. Aston also had a minor solo hit with 2015’s Get Stupid. In 2017 he was booted off Strictly mid-series after harsh words from judge Craig Revel Horwood, but says simply “He has the right to criticise. It’s his job.” He’s married to singer/actress Sarah Louise; they have two sons aged 7 and 5, and a 17-month-old daughter who Aston says is “the funniest person on the planet, a proper little diva – I come home stressed and she lightens my mood immediately.” Parenthood has changed him. “Before it was, ‘Get me out the house, get me working’. I’ve worked very hard for the last 20 years. Now, I want to be around them for as much time as physically possible.”

Jeff, who wed girlfriend Kate Dwyer in 2018, has two adult sons who he raised single-handedly after the death of their mother, tragic Big Brother reality star Jade Goody. Bobby, 22, plays Freddie Slater in EastEnders; Freddy, 20, is a model. “I never felt ambitious,” says Jeff. “I was just grateful to go to work and get back to pick the kids up from school. They’re responsible for themselves now, so it’s left a big space for me to grow professionally.”

Jeff worked as a barrister’s clerk before appearing in 2001’s third series of Channel 4 reality show Shipwrecked – “the opportunity came out of nowhere, then I co-hosted Dirty Laundry with June Sarpong.” His natural warmth led to a long list of TV bookings including I’m Famous & Frightened – “being scared on a regular basis” – Dancing On Ice and Celebrity SAS: Who Dares Wins. Last year Jeff and Freddy took on Celebrity Race Across the World for an emotional journey through South America. Brazier is also a qualified football coach, a grief counsellor, and an author; a regular modern-day Renaissance man. He is content, he says. “I have a great work/life balance. I’ve built a career on experiences. I’ve travelled a lot, I’ve met memorable people, I’ve tested myself… I have gone through so many challenges personally and professionally – and 101 Dalmatians is the latest. I guess that that’s the point of it all isn’t it? Rather than to do just the same thing all the time and never find out what else you had in the locker. I’ve built a life in taking on new things. Try anything and don’t worry about failing.”

101 Dalmatians is both a steep learning curve and “an opportunity to be playful”. The family musical is based on Dodie Smith’s 1956 book. Its stage and screen reboots include the 1961 Disney cartoon (where the henchmen were Casper and [itals] Horace [roman] Badun). It was written by Douglas Hodge (music and lyrics) and Johnny McKnight (book) from a stage adaptation by Zinnie Harris. The puppets, created by brilliant Jimmy Grimes, are adorable, says Jeff. “They move so fluidly, they are brought to life. The puppet director is meticulous. He’s constantly creating movements for them.” The updated story initially cast Cruella as that very modern evil, a social media influencer, although she’s now described as a fashionista. The musical was panned by some snooty critics when it ran in 2022. “Everyone is entitled to their opinion,” shrugs Aston. “You can’t please everyone. We’re just trying to hold on as much of the classic story as possible. It’s fully entertaining for families across the board.”

Jeff: “I can’t wait until his kids and my godson watch the show. They’re going to have such a lovely time.” Aston agrees. “We’re entertaining children for an hour and a half, it’s lovely. But remember, it’s quite a short run, so you need to go and see it now – or you’ll miss us. Don’t put it off!”

*101 Dalmatians The Musical runs at the Eventim Apollo, Hammersmith until August 30. For tickets and info visit 101dalmatians.co.uk