SATURDAYS' bombshell Una Healy has never been prouder than of her band's new album – and she thinks it'll shut up the snobs who snipe at pop's glamour girls.

The five-piece play their biggest ever Scottish gig at the SECC tomorrow, and Una's fed-up of them being dismissed because they're a pop act.

"I think a lot of people assume you aren't very talented because you're in a pop band," she says, with a lilting Irish accent.

"If you're in a girl band they think it's all make-up and fashion and you don't care about it. It's not at all like that. I love music, and I was writing songs from a young age.

"Yes, we love fashion, but we have a real passion for music, and want to show what we can do musically as well."

The group's new album On Your Rader sees the band embrace a much heavier dance and R 'n' B style than before.

It's also seen the girls become far more involved in song-writing, which Una, who was a singer-songwriter before joining the five-piece, has been eager to try for some time.

"I come from a songwriting background, but at the beginning we were still trying to find our sound," she says.

"We needed to get to know what our fans enjoyed, and this time we felt very comfortable going back into the studio.

"It's come at the right time, as it would have been difficult to do it at the start, but it feels right now."

And the songs themselves, which bash many an ex-boyfriend, were great fun to write, according to the bubbly 30-year-old.

"We tried to write in pairs, because five of us co-writing was too many," she says.

"I remember writing one song with Mollie King, and we just laughed all the way through. It was one of the funniest days I've ever had in the band.

"We'd be trying to come up with sultry lyrics and be laughing non-stop doing it.

"It was the most fun we've had together."

The new album only charted at 23, the quintet's lowest-charting record yet. But Una's enthusiasm for taking the album on the road is still strong, and she can't wait to return to Glasgow, where the band had their first ever headline gig, at the Armadillo in 2008.

"We've been to Glasgow so many times it's like a home from home," she says, warmly.

"We started our very first theatre tour in Glasgow, and we got such a massive response there as the crowds are so good, and we've got brilliant fans in Scotland."

And Una promises that fans won't be disappointed as the group have lined-up a spectacular evening.

"We're going to put on a massive show, with lots of costume changes, dancers, a full band, songs from the new album", she says.

"Even in rehearsals, you can see how well it's coming together, and it's much bigger than anything we've done before-

"Everyone will be in high spirits with Christmas coming up, so I feel like you can plan your night out around us. It'll get people in the mood for Christmas."

But the star, who's expecting her first child with England rugby star Ben Foden, will be doing all her partying onstage rather than off on the tour, the girls' biggest to date.

"I'm avoiding alcohol, but we tend to put so much energy anyway that when we come offstage it's straight onto the next show.

"The problem with that is you never see the nightlife because you're straight into a car and then you're off again. But we always love the people up in Glasgow, as they're so warm and welcoming."

Una's baby girl is due next March, and the singer admits she's overjoyed. Yet she's also quick to quash any rumours that becoming a mum could lead to the band breaking up.

It's unbelievable that there's a person growing inside of me, and I'm so lucky.

"It doesn't mean the end of the Saturdays, though. I've worked my whole life to be where I am today, and having a little girl doesn't mean I'm going to quit my job.

"Life goes on, and this is where I m right now, but I'm 100% committed to my band."

One future ambition of the girls might be to claim a chart-topping single, having twice taken the second spot. But Una reckons she'd prefer a lengthy career to a one-off mega hit.

"A No 1 single would be great, but it's not the be all and end all of things," she says. "We've had lots of Top 10 singles, and a lot of people are surprised that we haven't had a number one.

"A lot of bands come and go having had number ones and then they're gone by the next year, whereas we've got the longevity. It's not the end of the world if we don't get one."

l The Saturdays, SECC, tomorrow, 6.30pm: £19:50 - £32:50.