What did you think when you were asked to join the hunt for Toto?
"Don't use the word 'hunt'! I'm against animal cruelty! It's a search. Alex, if you knew me and you knew what I'm like with animals, you'd know that this was the perfect job for me. I've always been such a huge animal lover. Even back at school I used to give talks about endangered animals. When I was back on the show two years ago, I knew that I'd miss my mum and dad, but my dogs were the toughest thing to leave behind. When they brought them up to see me, I was in floods of tears! I just adore dogs and always have done. Also it's been great to get back with all the people who produce these shows. The viewers don't see that, but everyone who works on these shows for Andrew are absolutely lovely! It's like a big old family, really."
The dogs haven't always done as they've been told in the challenges. Are they troublesome to work with on camera?
"But don't you just love that?! They say, don't work with children or animals, but I love the devilment of it. I sit there shouting, 'Yeah - go wee up the scarecrow!' It's the unpredictable nature of it that I love. Like they say with kids, 'Out of the mouth of babes'. It's the same with dogs. They are unpredictable, but that's what makes them so darn loveable. I beg to differ with anyone who says they can't love a dog. If someone doesn't like a dog - don't trust them!"
How do you rate the standard of the final five Totos?
"They are brilliant. I think there was around 600 dogs in the auditions and these are the best five now. I think what this part of the show has done is really great for dogs because we've had so much bad press about them recently, and they are the most gorgeous creatures. I think it's great that the search for Toto has brought forward so many great stories about what these dogs can do. I mean they help people with disabilities, they are great with young children, and they provide great company for people in their old age."
Do you feel under pressure at all in picking the right dog? The winning Dorothy will have to perform with your chosen pooch!
"Of course! Not to sound too serious, but this is going to be a huge show. There is pressure on us to get the right dog. Not only will there will be a lot of nerves about having the right Dorothy, we also need to find the best dog to be her best friend, right by her side on that opening performance. As judges, we must make sure that we have the right pooch for that job!"
How has it been watching the Dorothies competing two years after I'd Do Anything?
"I was so chuffed to hear that Andrew was doing another show. I'm a great supporter of these programmes. For me, I tried for years to get to the West End. And the Nancy show finally gave me that chance. The programmes showcase so much talent, open so many doors, they fund massive singing events around the country, they fund people through college and most importantly bring a whole new audience to the West End. There is that stigma about it being a reality TV show, but I can't tell you how many people have come to me and said, 'Oh this is the first musical I've ever seen. I want to see another one'. I mean how brilliant is that?! I know it's great to sit back, put your feet up and watch TV sometimes. But there is nothing quite like a live performance at the theatre."
What advice would you give the girls in Saturday's final?
"When I went back for Week One, I sang 'As Long As He Needs Me'. But I spoke to all the girls backstage and told them, 'It doesn't matter who goes. Or when you go out. You are all winners'. The Nancys have all gone on to star in things like Wicked, Les Mis and Sister Act. It goes on and on. That's why these shows are brilliant. Because it isn't just about the winning act. So many positive things come out of these shows. That's why it angers me when some people get bitchy about them."
I think it is because people associate the show with programmes like The X Factor...
"I know, I know. With The X Factor, it does push new talent and has created some great popstars. But I think in Andrew's case, he did have a vision of bringing live theatre back. And I think it's great how they do fund people to go to drama school and put these live events on around the UK. It's not just about who wins on a Saturday night. I just love the whole thing, I could speak all day about it."
You have landed a role in the Monty Python production Spamalot. Are you looking forward to that tour?
"Oh blimey, it has been hilarious. The cast are so brilliant. And guess who came in the other day?! I absolutely cacked myself! Eric Idle. I just thought, 'Am I actually about to be the Lady of the Lake in front of Eric? Yep, yep. I am'. It's so brilliant because it's so different to Oliver!. I don't die and save a child in this one. I've got to make people laugh, which is great. But I've got so much coming up. I've got something I'm desperate to talk about, but not allowed to say anything. Plus, I've also got the John Barrowman tour coming up!"
I can imagine that will be fun with John!
"Yup, me and the John Barrowman. The Barrowman! We'll be tearing it up around the UK. It sure will be fun with the two of us. We are terrible when we get together! He's great and I just can't wait to work with him again."
Does Barrowman throw a good party in his dressing room after each show?
"My lips are sealed. I shall say no more! But I think you know the answer."
The winning Toto and Dorothy will be revealed on Over The Rainbow on Saturday at 7pm on BBC One.