Sean Hughes' recent extra-curricular activities couldn't be more diverse. First up there's his podcast, Under The Radar, now almost 50 episodes old and featuring everything from knockabout larks with fellow comics to serious interviews with, say, Steve Parrish, the chairman of his beloved Crystal Palace FC.

That sometimes caustic podcast manner is quite a departure from the role he finished a few months back, however. For three months Hughes played the chirpy Mr Perks in The Railway Children, an elaborate family production that boasts a working train onstage. Sharing that stage and a small dressing room with a full theatre cast must be a seismic shift from the life of a touring stand-up - but then that, it seems, is the point.

The increasingly envelope-pushing Irishman has brought a more theatrical feel to his stand-up sets in recent years too: his new tour show, Mumbo Jumbo, even features a tiny musical. But we kick off here talking Under The Radar, as when Hughes and I got chatting a few weeks back I'd just that minute finished listening to one in which he showcased a neglected comedy hero...

I've just heard your tremendous podcast with John Hegley - I can't remember him being interviewed at length like that for years.

It's funny, I did Mark Thomas this week and was then talking to a friend who said "he didn't let you get a word in edgeways," And I said "well that's what the podcast's about!" It's not a vanity project for me, I just love these people. If something funny occurs to me I'll say it, but it's very much about them, not about me. I talk enough in my life.

All I'm trying to do is give a forum, especially for people like John Hegley, who doesn't speak that often. I got a couple of texts after the John Hegley one went out saying "I've never heard of him before!" and that's exactly what I want. You have to bear in mind, I did years and years of radio so I know how to interview people. And I know when to pull back.

Any tricky ones?

I'm a huge fan of Talk Talk, and I had [the band's frontman] Mark Hollis on years ago, I was quite obsessed by the guy and I asked him a question that probably lasted about four minutes, to let him know how much I loved what they were doing - and his answer was "no." And that stumped me completely. I thought 'my god, where the hell do I go from here?' But I really do pick the guests carefully, I don't just have anyone on.

You have varied people too - like the Crystal Palace chairman.

That was phenomenal, he was so honest, and when he's being so honest I'm just going 'I'm shutting up here.' Just let him tell me things, y'know.

It might surprise people to hear that you've been in 'The Railway Children' recently.

I did it for three months, and it was a joy. Obviously as a stand-up you're used to being on your own, so I want to do it [theatre] at least once a year. I'm so used to turning up at some shithole, just going on and playing for two hours then driving home: I love being on stage but the rest of it I cannot stand. So it was beautiful being part of a family.

Wasn't it intimidating to go into though?

Oh yeah, and also I only had 10 days rehearsal, and they've all been there for a long time together, so they were already a family. It was like a soap opera: "oh, our doctor's son has just turned up." Also, I was doing a Yorkshire accent. The Railway Children is a kids show really, but the production is beautiful, it's on two platforms, the audience is on either side so you're never really talking to all of them at once. Learning to play to different parts of the audience; I'm used to having them in front of me, so that was amazing.

I had to learn so many new things there, and I did learn things that I will bring into the next tour - also, it's the fact that Yorkshire people talk so much slower than Irish people, so I'm going to really take it down. I was getting to the point where I was talking way too fast.

How did you find it playing to kids? You've done a fair bit of kids TV...

Yeah but you're never in front of them. I've always found in general, kids, they love my face, because they think I look like a monkey. It's just an interesting face. And I always try to treat them as little adults. I've always loved kids, I just don't want to live with them.

How did you deal with them in the show?

Well, they let me... there's a lot of silences in the show but I filled all of them up. There's one particular bit where the railway children wake me up, they prod me with a paper, and the line is "Oakworth", which is the name of the station. But I thought that was boring, so I put a different line in every night, to the extent that some of the producers were going "stop doing that - make it train related" and I'd go "no!" But I'd stay within character. That was another weird thing, even during the breaks I'd be speaking with a Yorkshire accent.

On the last week, everything [I said during that scene] was related to the cast, but not to the detriment of the show, little private jokes - when you're waking up from a dream you could be thinking about anything. On my very last night, it didn't work for the audience but I went "I love you all very much but I have to leave now." I think they found that quite heartbreaking.

It is!

There's a possibility I might go back in again, at Christmas, but they're friends for life, I'll always love them. I know that on the next tour I'll be thinking 'why is there no-one around?' All those little [dressing] rooms are depressing, but if they're full of people there's life there, we'd play music, our various relationships. Then you get to Maidstone...

How do you get the adrenaline going for a solo show, while you're sitting in one those dressing rooms beforehand?

Well I don't really get adrenaline anymore; when you do a two hour show you start off by just going "alright?" then you get into it. It's always got to be different, so what I tend to do is get six or seven people from the audience, and they become part of the show, that's the soap opera of the night.

I remember when I first started Life Becomes Noises, about my dad, I was bricking it, because I was going out to do a comedy show about the death of somebody that I loved, so it took me a good six months before I could really manage that one properly. I previewed it at the Soho Theatre, and I always remember that this woman really wanted to see me but her husband clearly had no interest, and he was on his phone all night, and it's one of those regrets that I didn't go "get off your phone and get out". But because I wasn't sure of the show, I didn't have the balls to do it then.

You wonder sometimes if people in the audience don't realise that the performer can see them, and that it might affect them?

It's only happened to me twice, another time was in Lincoln, Life Becomes Noises again, and there are points in that show where I just can't come off script, to make it work. There were these two fat guys in there, who were just mumbling and heckling, and I thought 'well they'll leave at the interval because they're hating it.' But I came back for the second half and they were still there, and after a two hour show they just stared at me and didn't even applaud.

There was a bit of me that just wanted to... I've done it since. I remember doing a gig at Finsbury Park, I was only doing a 40 minute set, but there were two guys absolutely trashed, drinking Captain Morgan, from the bottle: I could see focus was being taken away from me and the audience were looking up at them. So I said "security, get rid of them, now."

Does that not create an awkward atmosphere afterwards?

No, because they're totally on your side, because they can see that they're being arses. I try not to pick on anyone. I'm sure at times I can be overly cruel, but I don't mean to be - a line just comes out.

Do you enjoy doing club gigs again now?

What I like now is, when I turn up somewhere like Essex, and I'm headlining, and the rest of the acts have been alright but they haven't been great, and you just go 'bang! Here we go.'

Every show should be a one off, I always look at the local paper, and if there's anything decent in it I'll bring it up straight away. I remember playing Dunstable, and I don't know if you've ever watched that programme 24 Hours in Police Custody - it's people fucking people in graveyards, and they get 24 hours to see if they can get a case against them - and this was mainly filmed in Dunstable. So my opening line was, "I'm amazed there's anyone here, I thought you were all in fucking prison" - the very fact that you say something like that, they think 'ah, we can trust him.'

Presumably they could turn against you?

Absolutely, and people will complain, 'why are you having a go at...?' I left an agent because they said "we've been getting complaints because you played Manchester and slagged off Manchester. Why don't you slag off Liverpool? They'd love that." And I said "because I'm not a fucking hack comic." I'll never do easy stuff like that. I'll play tricks, and I'll use the tricks that I know, but I'll never do hack stuff like that.

You wrote an interesting tweet about the Channel 4 Comedy Gala recently: "Anyone who still thinks comedy can be truly funny over 4 minutes should get out of the business".

They're all good comics as well, but you go 'what the fuck are these producers doing?' Even with The John Bishop Show, they're giving someone five minutes. And he keeps saying they're his favourite comic ever, each week. TV really should take risks and let people do hours. Some people are gonna like it, some people aren't. So what?

They let stand-ups do specials in the States...

HBO do, but I don't think the networks do.

I don't know why Sky don't commission a load of hour-long stand-up specials. It wouldn't cost much, relatively speaking.

Absolutely right. Like Stewart Lee - at least he gets to go on, which I totally respect because I think he's great, but the only reason the BBC gave him his next series was because Sky said they were going to give it to him - he's very honest about stuff like that. But then the programme he did for Comedy Central did the exact same thing, made them all four or five minutes, and you're going "stop it!".

I read that there's music in your new show, Mumbo Jumbo?

Yeah, I do a musical about aging, there's a four minute piece where I put on a Fatboy Slim song and I'm dancing like an idiot to it [explains rest of routine, which we won't give away here]. The audience love that: it so annoys me that music can really bring a crowd together more than comedy!

The weird thing, because I've been doing The Railway Children, I haven't thought about comedy for fucking months, it's all encompassing. Since then I've managed to write a poem and a joke. Poems I only write when I feel it's really necessary. It's a bit like the two novels I wrote, I had to get them out of my system.

Is this show another concept effort?

They always are, yeah, this one's pretty much about how we're all addicts. It starts off about how when you see a homeless person, people say 'oh don't give him money, he'll only spend it on booze' and going 'what's your fucking problem, if he does that?' Mumbo Jumbo is about the daily battle that we all have, between common sense and mumbo jumbo in our heads, and sometimes the mumbo jumbo wins.

I'm definitely addicted to checking my phone, when I don't even need to.

Well that's what I mean, everyone is, and that's the media telling us that we need all this stuff that we don't actually need. I still buy stuff off Amazon, and I don't need it. We're all addicts. I quit drinking for a couple of years, and realised that I just swapped that addiction for something else. Which was ginger ale, Maltesers and decaf lattes.

Mumbo Jumbo is touring the UK until late November. Visit www.seanhughes.co.uk for details.