"It feels like ten years. Once you start thinking, and looking back over the 20 years, there's so much we've done," frontman Tim Wheeler told UTV.

Tim, Mark Hamilton, Rick McMurray and former member Charlotte Hatherley produced nearly 20 top 40 hits including Girl From Mars, Shining Light and Cherry Bomb, selling eight million records worldwide.

Tim dispelled the urban myth that Girl From Mars was originally 'Girl From 'Ards'.

"It was always a sci-fi song, so it never would have worked," he laughed adding that the reason they are still going strong is down to "a great lyrical hook and great melodies".

"I think that's something that stays constant for decades," said Tim.

"I think we've always kept the passion for it, there have been tough times but I think once we got over that very first difficult time between our first and third albums when our second album didn't do well and we managed, I think by working very hard on the third album I think that forged a strength," he said.

"We're schoolmates, similar to U2 who all went to school together and they're another band who has lasted a long time."

The band recently supported Coldplay at the Emirates Stadium, which Tim said was "amazing".

"I'm an Arsenal fan too, so it was like a home show in a way, only a different kind of thing with 65,000 people," he said.

He also helped raise £30,000 for Alzheimer's research last year, after the death of his father in January, by organising a special gig in the Ulster Hall.

The band takes to a smaller stage on Friday at the Oh Yeah Centre in Belfast for their anniversary gig. The venue takes its name from an Ash song.

"It's a great privilege that they named it after us in the first place," Tim said. "We were trying to think of somewhere in Belfast to do something quite intimate and so it made sense, it's just round the corner from the Penny Farthing where we used to do some of our first shows."

Stuart Baillie, founder of the Oh Yeah Centre said they are utterly delighted the band is celebrating their 20th anniversary at the venue.

"I was a journalist for the NME and first met them in 1994 and they were too young served in the pub so I had to interview them in a cafe," he said.

"They were incredibly sharp about the music and what they wanted to be and you could see that confidence in Tim Wheeler as an artist.

"When I came back home I set up a website called 'Oh Yeah' in 1998 after the song by Ash, to associate it with a great song and positive ethos. Tim has been a huge supporter of what we've done ever since, he's turned up at important moments with his guitar and played gigs and done songwriter sessions.

"Tears will be shed tomorrow night, some of the people who will be at it, it will be their first band that they fell in love with and have followed them all the way through, eight million records, 18 hits in the top 40, they're one of the best we've ever produced."