What first attracted you to The Invisibles?
"The script. Blinding script. Full, rich, funny – just one of those parts where you go 'bloody hell'. A: it's going to take some playing, and then B: it's going to be a real ride. In the first episode Maurice finds himself in this bizarre situation that he's come back from the 'Costa del Crime' because he's had a heart attack and he's promised his wife that he'll come back to the bosom of the NHS. She's picked out this cosy little flat nestling in this little seaside resort where people come to die. Needless to say, he's a fish out of water. At the same time, his mate [Syd] is asking him to go back on the job, but he's promised his wife he won't. His mate wins…"
Given that Maurice is a criminal, was it important to keep him a sympathetic character?
"Undoubtedly… Bill [writer William Ivory] set out to write an Odd Couple, like Walter Matthau and Jack Lemmon. In the same way that they say some unspeakable things, so does Maurice. It's more like an Ealing comedy heist… they have heart. They're what's normally termed as loveable rogues. In terms of being a criminal, it's more about him being at the top of his game. He's a safecracker. He's a locksmith extraordinaire. I got to work with some locksmiths during the shoot and there's not that much difference between a locksmith that's paid to open locks when people have bungled – and someone who does it [criminally]."
Your real-life daughter Emily plays your on screen daughter. How did you find working with her?
"Fantastic. Just bloody wonderful. She's such a lovely little actress anyway – and I don't mean that in a condescending way. I'm taller than she is! I was in Canada making a movie when I heard she'd got it. They said 'would I mind?' Good God, no! So consequently it was really, really enjoyable. There's real and instant chemistry between me and Emily that you see on the camera. It's magical."
What's the latest on the mooted Ripper spin-off with Rupert Giles?
"The latest is that I was over in LA last year at about this time. I bumped into Julie Gardner from BBC Wales who said 'has anything ever happened to that?' And at the same time I had just been speaking to Joss [Whedon] saying that there are a lot of people who keep asking about it. He said 'Is there anybody at the BBC I can talk to about it?' so I introduced him to Julie Gardner and they got on very well… and then the writers' strike happened and Fox picked up an idea of his called Dollhouse that he's doing with Eliza Dushku. So the answer is that there is a possibility of something happening… the story that he's written could adapt to being a one-off story not necessarily related to Buffy. All that means that there is the will and there is the means. It's a question of how, when and if it [comes together] through the next year or so."
Are you sworn to secrecy on the story details?
"Yes, in as much as I wouldn’t want to give it away. All I can say is that it’s a ghost story. But a ghost story with a real Joss Whedon difference. It’s got such a twist to it. But I wouldn't want to give it away. It would be the worst spoiler of all time."
Did you grow attached to the character of Rupert Giles?
"I grow attached to a lot of the characters I play. I've got attached to Maurice in The Invisibles even though he is a miserable old bugger. He rants and he's a grumpy old man but I still like him. He has a great integrity. A good soul. But I loved Rupert Giles."
Have you followed his new adventures in the eight season Buffy comic book?
"I've seen bits of it and I'd love to see more because it's so cool. It's Joss – and I love Joss's writing. I haven’t had a lot of time but I must get the whole season and check it out."
How is Merlin going?
"Brilliant. I've just shot a couple of weeks in France in this incredible chateau, in the most amazing location. Next week we go back into the studio. It's very exciting… it's Smallville meets Camelot, basically. The young actors who are playing the major roles are really good and very interestingly cast. The first block director James Hawes, who I worked with on 'School Reunion' for Doctor Who, is a wonderful director with such a great vision. He's definitely giving it an extremely classy stamp. It’s already been bought on NBC."
Are there any plans to resurrect your Doctor Who villain Mr Finch?
"Apparently not – and I'm not sure why! I think he should come back. He was good fun. There is a school of thought that he's dead, but you don't see him die. Who knows? I'm very fond of him and it was such good fun working with Mr Tennant. He's a lovely actor. So if they ask me I'd say 'yes' in a flash."
They say 'never work with children or animals', so where does K-9 fit into that?
"In both categories! I've worked with more responsive actors. After all this time, they might have worked out one or two more means of propulsion. He was quite slow off the mark and not always terribly consistent. But beyond that I know he's a lot of people's favourite, so I'm not going to diss him!"
The Invisibles begins Thursday, May 1 at 9pm on BBC One. To find out more about Anthony's recent project Repo: The Genetic Opera click here.