Dad's Army is back – but does it work on the big screen?

Steady chaps. Don’t panic. First they recruited the actors. “I was impressed with the excellent cast”, says Perry. Toby Jones, 49, and 5ft 5in [The Hunger Games, Captain America, an investment banker in last year’s Capital on BBC1], originally turned down the part of pompous Captain Mainwaring. “You have to be cautious taking on such a project, because there’s an enormous fondness for the show. We all thought it was mad to try to re-create it. Then I saw the script and cast and it became a selfish decision of mine to accept: there are some very funny situations, and I assumed the other actors would help me look good.”

Bill Nighy [Sergeant Wilson] was swayed by the chance to work with “the brilliant” Jones and Michael Gambon [Private Godfrey]. “He’s so amusing. We’d sit on the beach at Bridlington, east Yorkshire, [where filming took place], and he’d make me laugh until I couldn’t speak.”

Catherine Zeta-Jones had a nostalgic motive for playing a glamorous journalist, Rose Winters, allegedly sent by The Lady magazine to report on the Walmington-on-Sea Home Guard patrolling the Dover coast to thwart a beach invasion from the Germans in 1944.

“My family were fans and can recite some of the lines from the TV series verbatim. People ask, ‘Why remake a classic?’ Well, because it’s jolly good fun and introduces it to a different generation. The TV series stands on its own – the scenery wobbles, which is part of the fun – so we’re not trying to top it. It’s a real romp.

“The big attraction for me was working with great actors." Tom Courtenay is Jones, Blake Harrison [The Inbetweeners] plays Pike, and Sherlock co-creator Mark Gatiss is a colonel who warns the platoon there is a German spy in town. “I loved the make-up sessions with all those guys bantering, cracking jokes, flirting. You don’t know whether an ensemble will get on, but this was everything I wanted. It threw me back 20 years to The Darling Buds of May, working with people who just get it, know their lines and have no bulls**t. They don’t need deep therapy sessions before walking into a room. I’m not dissing American actors, but it was a blast, coming home, remembering what fun it was.”

It wasn’t all fun for Toby Jones. The plot meant he had to swim in the North Sea last November. “I wouldn’t wish that on anyone. I had to wear a fat suit, which gave me too much buoyancy so it was weighed down with weights. You suffer for your art."

Neither he nor Nighy, 66, based their performances on the original cast. “When you play a character for a half-hour show like Arthur Lowe did, it’s always funny,” says Jones, “but when you extend it to a movie the character has a certain nobility, which is endearing. He’s like someone who’s given up his time to run the local cricket club: everyone takes the mickey, yet they all depend on him. I worried about how to do the part – it can’t be an impersonation – but when we started the chaotic film schedule I became this character from a certain class with his foibles.”

Nighy concurs: “I can’t mimic anyone, so I just did it my way.” He met John Le Mesurier, the original Wilson, at the start of his career in 1981 when he and Le Mesurier were in Radio 4’s The Lord of the Rings. Nighy, who shares a sardonic view of the world with the fictitious Wilson, reminisces, “Le Mesurier always wore red socks. I’ve sat in shops trying to buy patterned or coloured ones. But I can only wear dark grey.” He explains this is due to his “sartorial fetishism”. He’s always elegant, languorous and, like Jones, charmingly self-deprecating and lacking in confidence. He won’t ever see the film because he has a horror of watching himself.

They both had late-flowering careers – Nighy gave up acting in the 1970s and worked on a market stall in Croydon selling womens’ clothes before he auditioned at the Everyman, Liverpool, then a socialist hothouse with resident writers Alan Bleasdale and Willy Russell. He went from there to the National Theatre where insecurity led to dependence on alcohol. He tells me, ironically, that Le Mesurier met Rod Stewart in Los Angeles when his son was in the band. “I asked him how it was. He said, ‘We do the work and get drunk. They do it the opposite way round’.”

Nighy had to wait until 53 for success when he won Baftas for State of Play and Love Actually, since then he has worked continuously on TV, film and theatre – last year winning plaudits on Broadway in David Hare’s Skylight. He had a 27-year relationship and a daughter (Mary) with actress Diana Quick, which ended in 2008. Now he prefers his own company, but says he thinks about death “12 times a day”.

Jones turned the disadvantage of his small part in 1998 as Julia Robert’s stalker in Notting Hill into a modest triumph when he wrote and acted in a well-received play, Missing Reel, fictionalising his disappointment that his scenes were cut. “I made a silk purse out of a sow’s ear,” he says. “I’d like to write but it’s hard to dip in and out and I’m lucky enough not to have the time.” He’s philosophical that two of his ‘breakthrough’ films were ill-timed – Infamous, in which he played a lisping Truman Capote, was released after what many considered an inferior film, Capote, on the same subject but which won Philip Seymour Hoffman an Oscar. And The Girl, in which he played Alfred Hitchcock was sidelined by Anthony Hopkins in Hitchcock.

It’s not even as if acting was his first choice of career. He rebelled against it as both his parents were in the business – his father, Freddie, still appears in Emmerdale, aged 88 – “when his knees allow. The great thing is he’s forced to spend time with young people, which keeps him young. It’s his absolute life blood. I can’t see myself doing it at that age, but we have the luxury of not being able to predict the future. I’m a lot less insecure than I used to be but I’m never sure I can do the job. Any actor would be mad not to be surprised by success: there are so many brilliant ones and the statistics of sustaining a career are totally against you.”

With such a huge melange of successful ones in Dad’s Army, egos must have been involved. “Of course,” says Jones, “but all of us are so well established we know that supporting the others is in our best interest. Comedy depends on where the joke is and it would be crazy to try to take it for oneself. A lot of traditional comedy results from hierarchies – like those in the Army – being debunked whereas contemporary comedy is more self-referential.” Perry quotes George Bernard Shaw, invoking an Irish accent: “The first thing about comedy is you must have reality.”

Up to a point. Zeta-Jones, 46, who won an Oscar for best supporting actress in Chicago in 2003, and married Michael Douglas in 2000, was enlisted to provide glamour, as well as a new character, journalist Rose Winters, who mesmerises Mainwaring, Wilson, and the others. “We also get to see their wives [Felicity Montagu plays Mrs Mainwaring, who was never seen in the TV series], so it gives a broader aspect.”

She returned to work in England in a much less stressful way than she left for America in the mid-90s when success proved elusive after Darling Buds and she became better known for her private than professional life. “I could foresee a career in England being put in a box where I didn’t belong. Whenever I stepped out of my terraced house in Fulham there was a blitz of photographers.” She married Michael Douglas and put her career on hold to bring up their children, Dylan, 15, and 12-year-old Carys.

“I wanted them to be in a very close-knit family, living in the country outside New York. We can’t forecast what will happen, but at least we’ve protected them from the craziness that goes around famous people. For sure they want to act. It’s hard for me to say no because I was in Annie at nine years old and their parents and grandparents are actors. I explain to my daughter what beauty is and, yes, we all ask if our bum looks big, but today there is extreme scrutiny. You have to deal with mean people hiding behind social media. I tell them that fame isn’t having eight million followers on Instagram. It’s hard work.”

Douglas had throat cancer diagnosed in 2010, she was treated for bipolar disorder in 2013, and they separated temporarily. “I didn’t want any of that to come out, but ironically it was the best thing that ever happened. I can now put it to one side and say, ‘Yeah, me too. Big deal’, facing up to it rather than pretending. I’m not interested in being ‘tortured for my art’. I’m probably the lowest-maintenance actress you’ ll ever meet, though we have to be barmy to go into this profession. I have many ambitions left. I’d like to do a one-woman show in Las Vegas, write, direct. I feel great now, enjoying doing what I want.”

Will the film work? Jimmy Perry is one of a very select few who have seen it on DVD. “It will either be terrific, or whatever. I liked what I saw, and won’t criticise anyone.” Toby Jones says, “I’m interested in how it’s received but I don’t worry. Hopefully we’ve honoured the original and moved it on a bit. Watching the other actors I often thought, ‘That makes me laugh’. You join a project, it goes out into the world, and you have no control.”

Are they doomed? “We did our best,” adds Nighy.