Dickensian spoof Bleak Expectations became a big hit on Radio 4 between 2007 and 2012. The show has now jumped to the stage. Here we catch up with creator Mark Evans to find out more about this West End run...

Hi Mark. For those not familiar, what is the Bleak Expectations about?

I always liked the way the original radio series was described: 'the story Charles Dickens might have written after too much gin'.

It's a fun-filled, family-friendly, rather daft Victorian tale of happy children turned into miserable orphans by their evil guardian and their attempts to thwart him and regain their life, family and happiness. All done with lots of jokes, silliness, farcical energy and the odd tragically funny death or two.

You don't need to know anything about Dickens to enjoy it - I barely knew anything about him when I first wrote it, just all those Victorian/Dickensian tropes of fog, misery, poverty and so on.

When you began 16 years ago, did you ever dream/hope it could head into other mediums like it has... a book, a TV adaptation, a stage show?

Honestly, when I wrote the first ever episode, I just hoped someone, would like it and maybe want to make it. Luckily, that happened... and then when we recorded the first radio series in front of a live audience they liked it so much that I thought 'hmm, if we added costumes and a bit of set this might make a rather fun play...'

Later on, when I actually read some Dickens - before each radio series I'd read one of his books for 'inspiration' but really to avoid having to actually start writing - I found myself thinking about putting the radio show into prose form. 'The dialogue's already written', I thought, 'so how hard can it be to add some adjectives and general description in between?' Which meant I wrote a book version.

I'm not sure it's entirely normal to do the same show in different forms, but this one seems to lend itself to that... and each version has different joys to it.

How close is the stage show to the original story, as told in the radio series/book?

The stage show is essentially the first radio series/the book, plus a bit of the second radio series. That seemed the natural way to do it, as the first series is the most obviously Victorian/Dickensian. (In later series the show goes a bit odder, having things like Martian invasions, zombie apocalypses, people's brains being put into dinosaurs and the main characters surfing a wave of molten brie on a giant cream cracker to escape the cheese mines of France... and that's all a bit too hard to put on stage!)

As to the work involved, I thought it might be relatively easy... but it turns out that wasn't the case! Getting three hours of radio into two hours of stage time meant losing a lot of material and then turning the story from half hour episodes into two one hour acts meant lots of re-shaping and re-inventing.

Plus, while in a sitcom the characters can essentially remain the same in each episode, in a play the do need to evolve a bit... so I had to add emotion where once there was only jokes!

The show has been running at the Criterion Theatre since May. How has it gone so far?

Pretty well, I'd say. The cast and guest stars are excellent and seem to be really enjoying themselves... and, more importantly, the same goes for the audiences, who genuinely seem to love the show. Some people clearly arrive not quite knowing what they've come to watch, and it's lovely to watch them gradually tuning into the slight strangeness of the show and starting to get it, going from quiet puzzlement to laughing out loud joy by the end.

The only issue is the size of the audiences... we're doing fine, but we could always do better - so please come and see it everyone!

Each week a guest star acts as narrator. You've had some amazing names take part so far, and some more coming up?

I think it's a really fun hook for the show and the cast enjoy it too - each week there's a different person to bring a new energy and feel to the show, helping to keep things fresh and interesting for them.

So far we've had Nina Wadia - who coped brilliantly with being our first narrator in the chaos of opening week, being hilarious on stage and lovely off it - followed by Dermot O'Leary, Sally Phillips, Robert Lindsay, Sue Perkins, Julian Clary, Adjoa Andoh, Craig Ferguson.

And do you know what? They've all been great in very different ways. But they've also been great human beings - which isn't always easy if you've got to go on stage after only a day or so's rehearsal!

Then in our last seven weeks we've got Lee Mack, Stephen Mangan, Tom Allen, Jack Dee, Alexander Armstrong and Stephen Fry - tell me that's not a great second half of the run! Pick your favourite and come and see what happens...

It's great Tom Allen, the original Young Pip, is appearing for a week. He was relatively unknown when joining your radio show, but is now a massive TV star!

It really is brilliant that he's coming back to play the older version of the character he played on the radio. Like you say, he's a mega-star now (which is thoroughly deserved by the way as he is both excellent and a top person) but he's always shown great loyalty to the show. He was such a funny Pip on the radio and I'm really looking forward to seeing his older, grumpier Sir Philip on the stage.

Given how keen everyone has been to be involved in the stage show, do you think the radio show could ever return?

Ooh, interesting question... and the answer is: I don't know. After writing thirty episodes I may be entirely out of ridiculous Victorian plots and jokes by now! Plus, there's the fact that the original Sir Philip, the legendary Richard Johnson, is sadly no longer with us. While having a different Sir Philip seems fine on stage, it somehow wouldn't feel quite right without his brilliance as Sir Philip on the radio. But on the other hand, never say never...

Finally, to end on a political point... shall we just give Gently Benevolent and The Hardthrashers a go of running the country for real. It might work out?

Well, at least Mr Benevolent always has a complex evil plan in mind, as opposed to our current politicians who seem to have no plan at all. And the Hardthrasher siblings would certainly help get things done with their mildly violent approach to every obstacle. It's not the worst idea anyone's ever had... shall we start a Bleak Expectations political party before the next election?