West End Girls, It’s A Sin, Love Comes Quickly, Actually, Very, Behaviour . . . the list is endless.

On Fundamental, their ninth studio album, they’ve teamed up with producer Trevor Horn for the first time since their 1988 No4 hit Left To My Own Devices.

The result is their best album in years.

The charming and witty pair met SFTW in their plush record company offices for a chat about making Fundamental, why they’ve gone political, working with Robbie Williams and what they think about the current state of pop.

How did you end up making an epic, orchestral album after initially saying you wanted it to be electronic, minimal club music?

Neil: It’s literally just what we wrote. There are some minimal moments — the first track Psychological, which I think is really good, and the track Minimal is, well, minimal.

I love this album. You spend so long writing and making the album.

It’s a beautiful album and has all sorts of moods - funny, sad, the whole thing.

To me, the sound of a record is so important and it’s been really well produced by Trevor Horn.

Chris: Trevor doesn’t do minimal, does he?

How did you team up with Trevor after working with some obscure dance producers on Fundamental?

Neil: We’d written The Sodom And Gomorrah Show and Luna Park and just thought they were Trevor Horn tracks.

We approached him to do one track, Numb, but a year ago we decided he’d be good for the whole album. We wanted it to sound consistent all the way through. Trevor is great at taking what you’ve done and running with it.

Trevor will go to any lengths to get things right. He’s very good at getting the feel of the track and taking it further.

Any in particular?

Neil: The Sodom And Gomorrah Show. We were worried because it was bit of a standard Pet Shop Boys stomper. Now it has the rock feel.

It is influenced by the Stuart Price remix of The Killers’ Mr Brightside.

I was thinking about 24-hour news channels when I wrote that song because it’s sun, sex, sin, death and destruction presented as entertainment.

And one of the tracks on the album was originally for Aerosmith! Tell us about that.

Neil: Chris had this bright idea to ask Diane Warren, the American power-ballad song- writer, to write a song. She ended up giving us Numb which she originally gave to Aerosmith. We thought it was really funny.

To us it was a sense of humour thing. Singing an LA power ballad Aerosmith had rejected – well!

How did you get David Walliams and Matt Lucas for the video for I’m With Stupid? Did you know before that David was an obsessive Pet Shop Boys fan?

Neil: They had said they wanted to do a video with us and that was the obvious one. In 1994 we were on Top Of The Pops for our single Liberation and there was this very tall, funny guy in the audience making funny remarks.

During the recording of it he was singing along to it which they then showed on TV. This mad tall guy who worked at the BBC was David Walliams!

Chris: The video’s great. They are really funny and do us better than we can.

The album covers such political issues as ID cards and immigration. Was that intentional?

Neil: It’s good to write about contemporary issues but in general I hate political pop songs. For I’m With Stupid, I was thinking about Blair and Bush but with humour. Integral is about ID cards which we feel strongly about but it’s done in a fun way.

We’re like The Beatles — we always have some serious ones, some funny ones, some ballads and ones you can dance to. Chris likes the more serious ones and I like the silly ones.

Chris: Neil would like Yellow Submarine and I would like A Day In The Life.

What did you learn about your own music from composing Battleship Potemkin?

Neil: We learned a lot about working with an orchestra and writing something very specific to a mood of a film. We learned we could do something differently if we wanted to.

Pet Shop Boys have always loved playing big, magical events. When we played it in Newcastle it went really well — there were 14,000 people there and it was a cold, cold night.

Chris: I think Battleship Potemkin will be something we will be performing for a long time because it exists as a piece and an outside performance.

You’ve been at the top for more than 20 years and have seen many pop trends go by. What do you think of pop today?

Neil: We are going through a phase where the term “pop” is used to mean rubbish. But bands like the Arctic Monkeys, Kaiser Chiefs, The Killers, Franz Ferdinand make pop music. They like to think they are rock but they are pop and all have a sense of fun about what they do and have a great look.

It annoys me that pop gets clogged up with Pop Idol and reality TV rubbish. Shayne Ward has a waxwork is in Madame Tussauds – can you believe it?!

But do you still see yourselves as pop?

Neil: Oh yes. One of the funny things about being the Pet Shop Boys is that we are so many different things. To some people we are MOR, to others we are dance and some say we are electronic, or the 80s, or a bit showbiz, and arty.

Chris: What we are is subversive, only a lot of people don’t get it!

You have a theory that bands have an “imperial phase” when you effortlessly do everything right. Do you still believe it exists?

Neil: Yes, our imperial phase was from It’s A Sin through to Heart.

Chris: It means you can do what you like, usually followed by disappearing up your backside!

Neil: Robbie Williams texted me and said: “I’m still imperial,” and I think he is really.

And you’re working with Robbie on his next album?

Neil: We can’t talk about that. But it was great fun performing with him on the Radio 2 show we did recently.

You once said you’d like to become backroom writer/ producers to let a younger duo take over. Does age bother you?

Chris: I’ve not written that idea off. Age doesn’t bother us but I do think there is ageism.

Neil: In rock music you are allowed to be the Rolling Stones and be 63 or whatever they are but pop music is uncharted territory. I’m 51 so we’re pushing the boundaries. We’re doing it because the young people aren’t.

What can fans look forward to next?

Neil: We’re doing load of festivals. We’re working with Es Devlin, the theatre designer who did the Kanye West Tour. She’s come up with a fantastic staging idea and we’ll have other singers and dancers on stage. We’re doing the Tower Of London festival and Bestival, plus a load of European dates and then a world tour.