Sally Thomsett interview: We sneaked out to a nightclub while making The Railway Children

As Sally Thomsett enters the central-London hotel around the corner from her home, the manager comes to tell her he is one of her biggest fans. Thomsett is overcome. “People are so sweet! Perhaps next time I do an interview he’ll let me use the suite.”

Thomsett has barely been on screen for more than four decades, and yet this month sees the re-release of Lionel Jeffries’s 1970 film The Railway Children, in which she played 11-year-old Phyllis alongside Jenny Agutter (Bobbie) and Gary Warren (Peter): three Edwardian children uprooted from London to a Yorkshire village after their father is accused of spying for the Russians. The breakthrough role earned her a Bafta nomination, while her comic timing and girl-next-door appeal led to her starring in a string of sitcoms throughout the Seventies.

Based on Edith Nesbit’s 1905 classic, that almost mythic film now has a sequel: The Railway Children Return. A hazy mix of Hovis-style visuals and homespun charm, it stars Agutter as a grown-up Bobbie during the Second World War, welcoming three evacuee Manchester children into her Yorkshire home.

Although Agutter is the most famous of the trio, playing Sister Julienne in Call the Midwife since 2012 and appearing in Hollywood films such as The Avengers, (while Warren and Thomsett both gave up acting in the late Seventies), was she miffed she wasn’t included in the remake? And what does she think of it? “I haven’t seen it, I didn’t even know they were doing it until recently,” says Thomsett (who was offered tickets to the premiere, which she politely declined). I think it’s lovely there is a more modern version for children. Although, I can’t imagine now, if a similar situation occurred and a family had to suddenly move to the country, that the children would be sitting on a fence writing messages to the kindly old gentleman on the train, as we did in the original! They’d all be on their iPhones instead.”

Thomsett is engaging company, eager to talk, and not at all stuffy. The naughty but nice twinkle that made her such a hit in the Seventies is still very much intact; I suspect she’d be good fun after a gin and tonic or two. Her features still recall the young Phyllis and I tell her I’ve always preferred that mischievous little girl – up to her neck in cotton petticoats yet always on the verge of exploding into giggles – over Agutter’s almost painfully serious Bobbie.

“Of course I wasn’t 11, I was 20,” Thomsett tells me gleefully. “But Lionel was so protective of the film’s image he forbade me during the shoot to be seen driving a car, drinking wine or hanging out with boyfriends.” This didn’t go down well with fun-loving Thomsett, who adored cars and glamorous men. “I got so bored I persuaded Jenny to sneak out one evening to a nightclub in Leeds. Unfortunately, Lionel happened to be there too, perched on a mezzanine level with our producer, dropping coins on to the head of a semi-clad woman in a birdcage. He was aghast to see us. I got into a lot of trouble for that.”

Of her subsequent roles it was the 1973 sitcom Man About The House that people remember most. Johnnie Mortimer and Brian Cooke’s innuendo-stuffed forerunner to Men Behaving Badly saw Thomsett and Paula Wilcox play housemates Jo and Chrissie, who take on a third, Robin, after finding him asleep in the bath after a party. “It was considered a bit naughty at the time. People didn’t share flats with people of the opposite sex,” says Thomsett. Did she find the humour sexist? “No! Anyway, back then you took everything with a pinch of salt.”

Yet while Thomsett’s spark and sunny demeanour made her a poster girl for 1970s light entertainment, she was also picked for darker roles. In 1971, she starred as 15-year-old cheerleader Janice in Sam Peckinpah’s Straw Dogs, a film so marinated in sadism it was banned in the UK in 1984. (Janice is accidentally smothered to death by a lover during sex).

Peckinpah was notorious for his demanding treatment of cast and crew, so how, as a barely 21-year-old woman, did she find him to work with? “Oh he lived up to his rep. You never knew who was going to be still on set one day to the next. But he and I got on like a house on fire. I used to go into his caravan at 6am every morning because he’d ask me. We’d have coffee with cognac. But there was no kissing, nothing like that. He just liked me and I liked him.”

Soon after Straw Dogs wrapped, Peckinpah asked her to appear in what would become Convoy, his 1978 cult classic about American truckers. “But when I read the script, I realised my character was a hitchhiker who, every time she got into a truck, took off her clothes. So I turned it down.” Around the same time, Richard Branson asked her to appear in a promo for his fledgling Virgin Records, perching in the centre of a large vinyl disc. “It turned out he wanted me to be naked,” she says. “I said no straight away.”

She once auditioned for Michael Winner. “He said to me, ‘Walk up and down,’ then turned to another guy and said, ‘Nah. I don’t want the old men w***ing in the front row’. I thought, ‘you dirty old man’. I mean, I looked about 14.” Thomsett, it turns out, had no trouble looking after herself. “As far as I was concerned, it was ‘sorry love, but don’t even think about it’.”

She never thought of herself as good-looking. “All my early reviews talked about my goofy teeth. I even stuffed tissues into the chest pockets of my dress when I auditioned for Straw Dogs because I thought I wasn’t hot enough.”

Thomsett had worked since the age of 11, after her brother bet her five shillings she would not appear on Max Bygraves’s Summer Show, which led to a career in children’s television. So, when in 1976 she fell in love again (following a divorce from her first husband), she decided to take a break: “It felt like time to have a bit of fun.”

But her new lover was not much fun after all. He punched her in the hip to prevent her wearing a bikini in a commercial. She left him for the Danish entrepreneur Claus Nielson, who proposed with a Ferrari wrapped in a pink ribbon. That marriage didn’t last either, and in the late Eighties she hooked up with plumbing tutor Paul Agnew, her current partner – though she is still legally married to Nielson, who has proved too Awol to divorce. She remains unbothered: “I’ve had enough of marriage,” she says.

While Thomsett chose not to work while raising her daughter with Agnew, Charlie (now 26 and also her PA), a television comeback in the Nineties proved impossible. “Reality TV had taken over and I was never going to do that. The comedies simply weren’t there. But it didn’t matter, we were having such fun together as a family.”

Yet with serendipitous timing, this might be about to change. She signed up to a new talent agency and has been approached with a couple of possible projects, both still at the pilot stage: the film, Magic is Murder, for which it’s been proposed she play a “minxy” ghost; and the TV show, Together, a homage to Seventies sitcoms. Ideally, she says, she’d love to play the part of a “funny old lady”.

To a large extent she’s still her cheeky Seventies self. If her lively Twitter feed, on which she regularly posts archive photos, is anything to go by, she refuses to take herself too seriously. “These days you are meant to be insulted if someone winks at you. But I’d love someone to wink at me,” she smiles. “I’d think it was very cute.”

‘The Railway Children Return’ is in cinemas from July 15