ERIN Boag knows how it feels to be in the Strictly Come Dancing final. She made it in 2004 with Julian Clary, coming third, and in 2005 she was runner-up with former athlete Colin Jackson.

So she knows how this year's Strictly contestants are feeling, ahead of tomorrow's final. "This is when they really want it," she says. "It's a battle to the end, and it's in the audience's hands. English audiences like the underdog, and the "J" word.

"The judges' marks don't count, so the hardest thing is engaging with the public. And everyone is chasing the 'floating vote' - when viewers vote for someone who gets knocked out, who do they vote for next? That's the vote they're all are after."

Adds Erin: "Strictly takes over your life. We see a snapshot on the show, but the contestants juggle so much - rehearsals footage, TV appearances, interviews. And often they have 'day jobs' too. It's exhausting.

"This has been a phenomenal series, the highest standard. All the finalists have worked incredibly hard, whether they're dancers or not."

In 2019 Erin steps out on her new tour with Strictly star Anton Du Beke. Dance Those Magical Musicals sees the nation’s favourite ballroom couple pay homage to shows they love, including Phantom of the Opera, Mary Poppins, 42nd Street, Wicked, Top Hat, Hairspray and Jersey Boys.

The couple are joined by the London Concert Orchestra, a West End dance ensemble and singer Lance Ellington.

"What comes with a great musical is an iconic soundtrack," says Erin. "Anton and I sat down and talked about our favourite musicals, we've put a lot in. We have a broad age range at our tours, so as well as shows like Top Hat we've included Wicked and Hairspray for younger audiences."

The costumes reflect the musicals, and Erin is hands-on with the styling. "I want to go out there feeling great, that's important to a dancer. We have a truck just for the costumes," she says. "If you took the curtain away, you'd see us frantically pulling off clothes, getting ready for the next dance. It's 'organised chaos' backstage, rather like Strictly!"

Erin started dancing as a child in New Zealand. "My parents were dancers and took me to dance classes. I was very sporty, I did netball, swimming and hockey, and dancing was just a hobby. When I was 15 I took it more seriously. I moved to the UK, initially for a couple of years, and have been here ever since. Anton and I have danced together for 21 years."

Erin left Strictly in 2012 to have her son, Ewan, but still follows the show. "Strictly inspires people, it changes mindsets about dance. When Come Dancing went out of fashion, people thought ballroom was uncool, but our world has moved on," she says. "I run a class and get men coming through the door - plumbers, joiners, builders. Strictly has made it okay for men to dance. Boys see strapping rugby and football players and cricketers dancing on the show and it looks cool. What a great legacy."

* Anton and Erin Dance Those Magical Musicals is at the Alhambra on Wednesday, March 13. Call (01274) 432000.