When Steve Speirs is recognised on the street, it’s usually by people who think they know him personally. If corrected, they might peer more closely and identify him as “that bloke from Extras” or “the guy from Sharpe’s Peril”.

But things are changing for the burly Welsh actor.

“I was in a cab the other day and the driver said, ‘You’re Steve Speirs aren’t you? I saw that thing you did on TV the other night – it was awful.’” He gives a big belly laugh: “All I could think was, ‘He knows my name!’”

Clearly the 48-year-old is going up in the world. But in truth, he has been for a while.

Just ask Star Wars fans, who continually mob him at conventions thanks to his role as Captain Tarpals in 1999’s The Phantom Menace, or the members of the Facebook group that celebrates Speirs as “pathetic loser” Dullard in Ricky Gervais’ Extras.

Dig a little and you’ll find Speirs’ name everywhere, from Hollywood blockbusters like Pirates Of The Caribbean, Dead Man’s Chest, to TV staples such as Doctor Who.

When we speak, there’s extra reason for strangers to squint at him in the pub because the last episode of BBC One classroom sitcom Big School has just aired, starring Speirs as Mr Barber, a geography teacher on the edge. Bullied by the children, falling apart in front of colleagues and with a crumbling home life too, it’s a shambolic role perfectly suited to Speirs’ deadpan demeanour.

“Oh I loved playing him,”

he says. “He’s damaged goods, a man who wears his heart on his sleeve and I love that about him. But he really cares about the pupils and that shows. You can always spot the teachers who don’t – they usually become heads.”

Written by David Walliams – “a very charming, quiet, intelligent man” – the show depicts school days that couldn’t be more different from Speirs’ own. “When I was at school, if you misbehaved you’d have to wait at the bottom of the corridor for a teacher with a cane. There’s a completely different relationship between pupils and teachers now and it’s much nicer.”

The son of a former Hoover factory employee father and nursery nurse mum, Speirs grew up “a little bit of a show-off” in Troedy- rhiw, in Merthyr Tydfil, Wales. Acting was always an interest – his parents were bemused but supportive – but so too was rugby. He admits to being “a bit of trouble” at school but managed to get away with it on account of his talent for Wales’ favourite sport. “You could get away with murder if you showed any sign of being good at rugby.”

For a time, he was torn, quite literally, between the sports field and the drama studio. “My sports master, like my peers, didn’t understand my interest in drama whatsoever. He couldn’t see why I’d want to do anything but play rugby and he and my English teacher would fight over me sometimes.

I’d be in the middle of a scrum at the beginning of my lunch break then on stage as Oberon for the remainder.”

A taste for performance runs in the family; Speirs’ brother is professional opera singer Jeffrey Lloyd-Roberts, currently appearing in the title role of Opera North’s Peter Grimes. His sister is a teacher: “A very good one, no ideas of headship,”

he observes dryly.

Speirs went on to study drama at Loughborough University but continued to play rugby alongside until his agent suggested he stop.

“I’d turn up at auditions for pantomimes looking like I’d been in a car crash, which limits your work a bit.”

These days he limits himself to coaching young rugby players in Brighton; he has lived in Patcham since 2000 but enjoys commuting into London along with the rest of the city’s thesps “always on the 10.20am train – when the prices go down!”

It was during his university days that he first met Gavin And Stacey star Ruth Jones when they both appeared in the National Youth Theatre.

The pair have remained firm friends ever since – they’ve just been filming a new series of her Sky1 comedy drama Stella in Wales.

“I have huge respect for her as a writer and character actress, she’s fantastic. When she asked me to come on board with Stella [he plays Big Alan Williams] I was delighted. It’s lovely to work with people who are not only talented but good friends too.” He also knows Rob Brydon – there was a time when the three of them would knock about together at BBC Wales – but he laughs at the suggestion they are in the select band of Welsh stars that make up the so-called ‘Taffia’. “I’m on the outside,”

he insists. “But maybe if I work hard...”

He has rarely been out of work since graduating, although is often cast in rather unflattering roles.

He was Loquasto in fantasy film Krod Mandoon And The Flaming Sword Of Fire, an oafish servant “who belongs to a race of pig-like creatures known as Grobble”.

And, in children’s fantasy Inkheart, Speirs played Flatnose, a henchman with a face euphemistically described as “distorted”.

He remains particularly grateful for the opportunity that Extras presented; his episode became one of the series’ most popular and forged a friendship with Ricky Gervais and Stephen Merchant, who were so tickled by his performance as Dullard they went on to write a part especially for Spiers in their 2010 coming-of-age comedy Cemetery Junction.

Has he plans to work with the pair again? “Oh, they ring me constantly but I keep telling them I’ll let them know when I have some time.” He gives that big laugh again. “No, I think it’s more a matter of them letting me know if they want to work with me. But they’re great and of course I’d love to.”

In the meantime, he’s keeping his fingers crossed for another series of Big School and looking forward to returning to his roots on the stage at Christmas when he appears as Abanazar in Aladdin in Rhyl.

“I’m actually really excited about it. It’s been a long time since I’ve been on a stage. I’ve been really lucky in getting to play roles that are different every time. I’m still waiting to be offered the romantic lead though...”