It’s honestly up there with the most controversial couplets of all time. When Kate Nash sang the lines “You said I must eat so many lemons 'cos I am so bitter / I said ‘I'd rather be with your friends mate 'cos they are much fitter’” a nation fell in love, fell about laughing and vomited into its collective cornflakes.

It was the pronunciation wot dun it, of course; the fatal rhyming of ‘bitt-ah’ with ‘fitt-ah’ that turned normally god-fearing folk into spitting, fiery daemons of class warriordom in a way that the assembled hordes of lagered-up indie bands claiming working class roots could never dream of.

Reservations about class tourism aside, however, ‘Foundations’ was without precedent. It was simply leagues apart from the ropey electro grind of Nash’s much-lampooned first single, ‘Caroline’s A Victim’, its indelible chorus, replete with fluttering, heart-in-mouth strings taking the single to number two before the attention of beeb radio airplay.

But accusations that Nash is the prissy middle class girl playing chav to latch onto current trends have persisted, and the lady in question is most definitely bovvered.

“I don’t care if you think I’m fake,” says Nash. “I couldn’t give a toss basically because what does that even mean, y’know I’m not made out of plastic.

“I just feel like saying fuck off to those people. I don’t like negativity. I’m up for trying things and encouraging people to make music, you don’t have to be Jimi Hendrix to pick up a guitar, I’m certainly not but if someone has a problem with that they don’t have to listen to my music and that’s fine.”

She pauses, before reverting to the more familiar cant about ‘rising above’ the jibes of her detractors:

“I’ve stopped reading any press, as soon as the album came out I was like ‘end of’ basically. I don’t read other people’s album reviews anyway so I just thought why put myself through that, I’ve put so much work into this. All the stuff’s on there because I think it should be on there. I don’t need somebody I’ve never met to tell me I’m rubbish.”

“ A while back I met Simon Pegg who I absolutely love, he had my first vinyl and really liked my songs, and when you meet people you really respect you think ‘yeah, actually, I feel like I’m doing the right thing.’”

The follow-up single, ‘Mouthwash’, drew complaints of another kind – regarding her lyrics, which admittedly at times are so banal as to border on the absurd. Does Nash think it’s a valid line of criticism to argue that, as much as a person might enjoy cups of tea and beans on toast, it might not warrant inclusion in a song?

“Well I wouldn’t want to write about the same things all the time,” she says. ”I’d like to change and grow as a writer, so hopefully I’ll have different things to say with the second album.

“But with ‘Mouthwash’ I read this play called Guardians about a female soldier that was pictured torturing Iraqis. There’s a monologue from her and the one thing she says she couldn’t get out of her head was these women buy toothpaste, like they’re in a totally different world but they’re the same as her.

“When you strip away everything from someone you have the same basic needs like brushing your teeth so this was saying don’t judge me... it’s a bit of a protest song really.”

On the flipside Nash’s lyrics hold a certain fascination, like stumbling across the contents of a schoolgirl’s diary, although she insists they’re not purely autobiographical.

“Usually it’s a mixture of both,” she says. ”Like if I’ve had something happen to me or one of my friends then I’ll create characters round that. So some of it’s really true and some I’ll just let my imagination run away with me.

“You’ve got to have a certain amount of truth in your art for it to connect with people but you can dress it up and make it funny or horrible or whatever. ‘Foundations’ is about this relationship I had that just got all bitter and weird by the end of it, but I’ve watched my friends do the same thing with their boyfriends.”

A lot of the songs on Made Of Bricks are about failing relationships, but Nash doesn’t see herself as being a cynic.

“I’m a romantic I think, the relationships I’ve had have just been really flaky, like three to five months of nonsense and bullshit, you know I’ve had guys who have just not been very nice to me. But I’m not cynical, I don’t worry about any of that.

Does her romantic side mean she’s always disappointed?

“Well I’ve been hurt but I think you should wear your heart on your sleeve. I’m not afraid of being stupid or of someone seeing me at my weakest and then leaving me or whatever, I think human beings will do that to each other, you know you hurt the people you love the most. But I’m very optimistic and I love people, I just acknowledge there’s gonna be bumps along the way.

Elvis Costello once said he hit a point where he would try to sabotage relationships so that he’d have something to write about, but Nash looks bemused at the suggestion that she might one day follow suit.

“I think I’d give up if it ever came to that, just write about flowers and stuff. But I don’t always have to write about relationships.”

If proof were needed of Nash as the consummate modern day pop star then her ‘blog-happy MySpace page is surely it, stuffed to the gills as it is with name-drops of semi-obscure leftfield artists such as Jonathan Richman and Devotchka. Nash sees no problem with this:

”I never thought I was gonna be commercially successful but now I am which is cool, and there’s nothing wrong with pop music. But then I think it’s pop music that’s genuine like The Beatles used to be, before it got cool to get loads of guys in business suits who don’t know anything about people, to write songs for guys and girls who have fake tans and choppy haircuts.”

“I think it’s fine to have that list there just to encourage people to look into music they might not have heard before.”

Maybe it’s the posh-girl-slumming-it accusations, but Nash’s interviews tend to be peppered with allusions to that mantra of the celebrity age, ‘realness’. And yet she has expressed admiration for artists who are anything but, from Björk to Kate Bush to Regina Spektor. Does she think there's still a place for a sense of other-ness in pop?

”Well for me someone like Kate Bush or Bjork really is real,” Nash argues. “Obviously they have that amazing theatrical thing which I’m really into, but this is just who I am at the moment, you know I started doing gigs at a pub in Harrow so I’m not in a position to do that kind of thing.”

In contrast to the everydayness of the bulk of her lyrics, Nash also exhibits a certain kookiness and empathy with outsider figures on tracks like ‘Skeleton Song’ and ‘Mariella’. The latter is particularly interesting in the context of the parlous interviewee sitting across from me, a story of a girl who glued her lips together and wore black to make herself appear more mysterious.

“Yeah, it’s like when I’m in a room I’m just like ‘bang, bang, bang, loud opinions blah’ but sometimes you’ll have someone in the group that never really says anything, and when they do everyone’s like, ‘well you said that so it must be right’, you just really respect it ‘cos they don’t give it all away.

“I wish I could be this Emily Strange character living in her own little world who doesn’t need anything.

“I like children and their mindsets, kids make up stories and they’re just so crazy, and that’s what I try and do, just don’t give yourself boundaries. It’s a funny world, this industry, and I could get wrapped up in it if I wanted to, but that’s why my album’s called Made Of Bricks, ‘cos my relationship with my family is really strong and they really look out for me.”

Nash is understandably piqued at the ‘Mini Allen’ tag which has followed her from the outset and attributes much of the name-calling to a latent sexism in the music industry.

“The press would have really loved to make a feud between me and Lily but you just get past it by supporting each other,” she says. “Women get penalised so much in this industry so you’ve got to be on the same side.

“And then you have the press calling everyone ‘Mini Allens’, you know there’s always room for another band with the exact same set-up, which is fine, but why doesn’t that exist for women?”

Nash is protective not just of her own music but of the clutch of artists following in her wake: “Female singer-songwriters are in fashion now and it’s like there’s only room for a couple more, then it’s ‘sorry girls, back to bands’, and grouping people like Laura Marling, me and Adele together as Mini Allens is harsh ‘cos we’re totally not.

“Just listen to our music and if you can’t hear the difference then please go and get an education.”

Whether that’s the same education which produced the grammar-mangling songwriter of Made Of Bricks is a moot point, but Nash's message to her critics is clear: "why you being a dickhead for?"