“I was dressed up as a dragon, and we were singing the dragon song,” the junior schools minister Sarah McCarthy-Fry tells me.

It may sound like the Portsmouth North MP is giving an insight into her dreamy subconscious, but she is in fact telling me about a recent visit she made to her old infants’ school when its music festival was taking place.

“It was not a spectator sport - you had to join in,” she says, mimicking a teacher’s tone.

Ms McCarthy-Fry is entering her sixth month at the Department for Children, Schools and Families. Prime Minister Gordon Brown brought her in to replace Lord Adonis, a move that surprised many considering Lord Adonis’s popularity and experience in the role.

Relatively unknown politically, she moved from working as private secretary to Geoff Hoon, then Chief Whip, into her first ministerial role in which her principal policy areas are the primary curriculum, special educational needs and school admissions.

Our meeting coincides with the release of a Commons select committee report which calls for the national curriculum to be slimmed down and taken away from central government control. But I am advised that she won’t have much to say on the issue.

“I only do primary curriculum,” she says firmly. It soon becomes clear that the junior minister is not one to veer away from her strictly defined areas of responsibility.

However, once we move into these areas - explaining the Government’s plans to reduce the attainment gap for children with special educational needs, and the work she is doing in 14-19 education - she begins to talk with greater authority. But it is when she discusses her personal history that she really begins to loosen up.

Ms McCarthy-Fry grew up in Portsmouth. Her grandfather was a dockyard worker who was often found standing on a soapbox at the dock gate, espousing the benefits of the nascent Labour Party. Her father, too, was a trade union activist, so politics was discussed “at length” in the family home.

But, like a number of her New Labour colleagues, she attended a state grammar school and enjoyed the education that the selective system afforded, although this didn’t influence her political beliefs.

“I loved school,” she says, laughing. “I was such a creep - I really enjoyed school. I attended Portsmouth High School, which was a rather old-fashioned all-girls school.”

It was, she says, “an excellent education”, but one that she would not ultimately endorse across the country. “The only thing I would say about my school was that it was an excellent education, but it was also a very narrow education,” she says. “It was very academically focused.

“I have since been a school governor, a local education authority governor, I was chair of the PTA, and I was able to see how education had broadened.

“It was different times when I attended school. It was a long time ago - 1966 to 1973 - so education has changed dramatically since then.”

When asked whether her reference to this “narrow” approach is a criticism of grammar schools today, Ms McCarthy-Fry admits that she doesn’t have “enough knowledge” of such schools to know.

“I suppose my criticism of the grammar school system is that so many kids are missing out,” she says. “When I think about primary school and the small number of us that went on to grammar school, why shouldn’t that excellent education be open to every child?

“At the age of 11 to say, ‘OK, you can have that sort of education and the others can’t ...’ That would be my criticism.”

Despite her “excellent” education, Ms McCarthy-Fry did not go on to university. She started a family early in life and was soon a mother of two living on a council estate in Portsmouth.

It is this part of her background that forms the backbone of her political ethos. Hers is an against-the-odds success story, and one she tells with pride.

She confesses that from the age of 11 she wanted to become the first female prime minister, and although that accolade has now been spoken for, she has overcome some sizeable obstacles to reach her current office. It is perhaps this that Mr Brown saw when he gave her the job - particularly when it comes to her work with 14 to 19-year-olds.

Ms McCarthy-Fry had her first child at 20, her second at 22, and was living in a sink estate with apparently few aspirations. But she began to study again - “at the kitchen table and after the kids had gone to bed”.

For that reason, she is able to use herself as an example to those young people she deals with who believe their life chances are dwindling.

“This is what I say when I go to schools,” she says. “I’m very eager for them to realise that at no point do we the Government shut off opportunities for young people. At no stage do we say, ‘Right, at 11, if you haven’t got what you need, that’s it. At 18, if you haven’t gone to university, that’s it.’

I say: ‘Look at me - I didn’t go to university. It’s a lot better if you do it at 18 or whatever - it’s an awful lot easier. It was a hell of a lot tougher how I got my qualifications. But don’t think because it hasn’t happened now that that’s you’re life. The door is never closed. And you can never stop learning.’”

This is her trump card. There are few Conservative or Liberal Democrat MPs working in education who can tell a similar story.

According to Ms McCarthy-Fry, it was during her time living on a council estate that she became politicised. She recalls the book which she cites as her favourite - Robert Tressell’s 19th-century socialist novel The Ragged Trousered Philanthropists - and describes how her “eyes were opened to inequality”.

But can the Labour Party today really allow her the opportunity to tackle such inequality. “Of course - that’s why we do it,” she says.

She is an unflinching supporter of New Labour, something reflected in her reply to my invitation to name her favourite Secretary of State for Education since the Second World War - apart from the current incumbent, Ed Balls.

“It’s going to sound awfully trite if I say Ed, but I have to say what I really admire about Ed is, yes he’s the Secretary of State, but we are very much a team here - and we’re very much about the whole child,” she says.

“The decision to change the Department for Education and Skills to the Department for Children, Schools and Families was absolutely inspirational. The way we’re looking forward to education in the 21st century, as opposed to the 20th, comes back to the view that education is narrow.

“Schools in the 21st century can’t operate in silos. And we can’t look at the child just in relation to what happens in the school.

“The fact that this department covers so much more than just schools, and is actually about the child as a whole, is directing us to where we are going to take schools in the 21st century, which is very much about schools being the centre of the community.”

While her website does not list education among her main political interests, Ms McCarthy-Fry says she “couldn’t have chosen a better portfolio” to work on.

“I feel very passionately that the key to changing the life chances of the people I’ve grown up with, and the people in the city I live in, is education,” she says.

“To be in a position to influence that is just amazing. I couldn’t have wished for a better department.”

With possibly a year to go until the general election, it will be interesting to see how strongly the Department’s ministerial team will feature in Mr Brown’s campaign.

But rest assured that Ms McCarthy-Fry will be on message every step of the way.

McCarthy-Fry CV

1994: Elected to Portsmouth City Council

1994: Stands for European Parliament: unsuccessful

1995: Portsmouth council deputy leader

1997: Stands for Parliament: unsuccessful

1999: Stands for European Parliament: unsuccessful

2000: Leaves politics. Focuses on career as financial controller for defence company GKN Westlands. Works in the US and Germany

2005: Elected MP to Portsmouth North

2006: Parliamentary Private Secretary to John Healy, Financial Secretary to the Treasury

2007: PPS to Chief Whip Geoff Hoon

2008: Parliamentary Under Secretary for the Department for Children, Schools and Families.