Sharleen Spiteri is laughing at the memory of what she was like at 21. “I was a little s***!” she says.

“I thought I was so punk. It’s only now, at 46, that I really don’t give a damn.”

Only she doesn’t use the word “damn”.

It’s nearly 25 years since the former hairdresser swapped her scissors for a guitar, forming rock band Texas with brother-in-law Johnny McElhone.

But age has yet to mellow her. With her dirty chuckle and sudden outbursts of profanity, it’s not hard to imagine her as the chippy kid she once was.

“I don’t really feel any different,” she remarks. “I look at a song like I Don’t Need A Lover [the band’s first single in 1989] and I still stand by everything I wrote.”

Things have changed a lot since then, of course. Although Spiteri is still handy with a hairdryer – she cuts her 11-year-old daughter Misty’s hair, as well as her chef boyfriend Bryn Williams’s – she has gone on to become a bona fide rock star with a clutch of top ten hits under her belt, including Say What You Want, Black Eyed Boy, In Our Lifetime and Summer Son.

The band’s eighth album, The Conversation, came out in May.

Her tomboyish, androgynous look has made her something of a style icon, to her continued bemusement. These days she’s as often spotted in the front row at fashion weeks as on stage at a music festival.

I just look like a boy!” she laughs.

I dress for comfort mainly. If I can’t jump about on stage in an outfit, it ends up on the floor. I turned up at the Lanvin show at Paris Fashion Week in trainers because I’d had to get a motorbike across town.”

But despite the fashion shows and the circle of A-lister friends – Gwyneth Paltrow and Stella McCartney are close pals – Spiteri says she has never been interested in the celebrity circuit. Rumours of wild parties with the Primrose Hill set were just that – “I’m not a big party person.”

I ask her when she first realised she was famous. “I don’t think of myself as famous. [Comedian] Peter Kay said to me, ‘The thing with you Shar is in your mind you’re still a hairdresser’ and I think he has a point. Fame can bring some very nice perks – it’s great when you need a table, or when you’re invited somewhere you’d never have chance to visit otherwise – but that’s it.”

In her family, manners and fairness were key, she says. They lived primarily in Glasgow (Spiteri’s accent is still strong) but travelled extensively due to her father’s job as a Merchant Navy captain, and she and her sister were introduced to new countries and cultures at a young age.

“It opens your mind. I don’t care where someone comes from or what they do. I think everyone’s equal and I’m a big believer in the idea that manners cost nothing. To this day, if my parents saw me being rude to someone, I’d get a clip round the ear.”

I can’t help wondering how that ties in with some of the singer’s reported outbursts. Didn’t she call Liz Hurley a “rude, fat b****” in a spat earlier this year? Ah, but that was in retaliation, she says. As Spiteri told the Evening Standard, Hurley had invited her over for dinner and then pretended not to know who she was.

“I said, ‘Oh hello,’ all polite, and she was like, ‘And you are…?’ Well, that was it.

‘Ali Baba,’ I said. The whole table drew back in their seats and you could see them thinking, ‘Oh God, this is going off.’”

What about telling Bob Dylan to – let’s put this euphemistically – “sling his hook” then? “That was an accident,” she says sheepishly. She was at the Lausanne Festival in Switzerland where Texas were sharing a bill with Dylan and others, and was relaxing in a dressing room Portakabin with her bandmates when she saw a hooded figure standing at the window in the mist. “I thought he was a pervert.” With a few choice words she saw him off, only realising it was the music icon as he fled.

Nonetheless, she says she doesn’t regret anything she’s said, Dylan aside. “I don’t take lightly what I say. I don’t just open my mouth. I have to feel strongly about something to actually cause a fuss and when I do say something, it’s exactly what I think.”

And you can’t help but applaud her reaction to hotel heiress Paris Hilton when she spotted her standing on coats at a party. “She wasn’t listening, she was wasted. So I filled my straw with my drink and I blew it. That got her attention.

‘Have some manners,’ I said.”

It seems a redundant question but has Spiteri ever felt pressure to conform? The music industry is, after all, notorious for trying to shape musicians into marketable acts. But clearly this is not a problem the straight-talking Spiteri has ever faced.

“You can’t be arrogant and do exactly what you want – you have to be open to suggestions – but as far as I’m concerned these are our songs, our music. If you truly believe something isn’t right for you it’s important to stand by that. Sometimes you’ll get a reputation for being a pain in the a*** but making music is my dream and if anyone comes in and tries to mess with that you have to say stop.”

Clearly her attitude has rubbed off on her daughter. She tells me she walked in on Misty and a friend looking at an internet video the other day. It turned out to be the infamous video for a single by pop star Miley Cyrus, which sees the 20-year-old singer swinging naked on a wrecking ball – the one which prompted singer Sinead O’Connor to write an open letter to Cyrus urging her not to let herself be exploited by the music business.

“She said, ‘Mum you have to look at this – she looks like a d***!” I looked at my daughter and thought, ‘You’re all right aren’t you? You’re going to be fine.’”

*Texas play the Brighton Dome Concert Hall on Thursday, November 21, at 7pm.

For tickets, call 01273 709709.