She's just back in Glasgow from a weekend away with her boyfriend and her bedroom is a mess. There's a big pile of washing on the double bed and a half-unpacked weekend bag lies in one corner, while a hairdryer and an overflowing sponge bag lurk in another.

A fold-down chair is strewn with flip flops and sandals, and the Roman window blind is still down. Then, to cap it all, as the leader of the opposition in Scotland attempts to switch on a bedside lamp to look for her hairbrush, the light bulb pops.

But Nicola Sturgeon remains unfazed - at least on the surface. She swaps the bulb from the lamp on the other side of the bed and gets on with it. With this act, her big secret is revealed: her built-in mirrored wardrobe is full of shoes. High-heeled, strappy little numbers they are, in every colour of the rainbow, with labels such as FCUK, Dune and Kurt Geiger.

''I have a weakness for shoes, especially high-heeled ones,'' confesses the Scottish National Party's leader at Holyrood, and the first woman to lead a party in a UK parliament since Margaret Thatcher. At 34, she also happens to be one of our youngest female MSPs and, at barely 5ft 4in and a neat size 8, she's definitely one of the smallest. ''But unlike Mrs Thatcher, I hate handbags. I borrow one of my mum's if I need to look extra smart,'' she says.

Shoes, she explains, are a way of making her mark in a profession that requires her to wear ''dull suits'' all day, although she does insist they are mostly of the trousered variety. Her shoes also give her some much-needed height in her daily combat with political rivals and relative giants David McLetchie, Jim Wallace, Robin Harper and Jack McConnell.

Nicola's life has changed beyond all recognition since she became deputy leader of the SNP in September and declared her intention of defeating the first minister in the Scottish parliamentary elections scheduled for 2007. At the same time, the venerable Alex Salmond was voted in as the SNP's national leader, and heads the party at Westminster. Nicola is now under constant public scrutiny.

''My job means I have to think about my clothes. One of the features of being a woman in politics is that, unlike a man, people focus on what you wear,'' she says as she attempts to clear away her holiday gear. ''If I turned up with the same suit two days running, they'd notice. Yet my male colleagues can get away with it - they only have to change their shirt and tie.''

The number of suits she has had to buy - without any clothing subsidy - has increased dramatically as she has become more prominent politically. Her small wardrobe is jam packed - the sliding doors won't close - and that's with many of the suits in question currently being kept at her boyfriend's house in West Lothian. He is the SNP chief executive Peter Murrell.

Today, Nicola's working outfit is beige tweed flares and a tight-fitting aubergine shirt, both from French Connection, with a broad belt and stiletto winkle-picker boots by Dune. She says her aim is to look modern but not too trendy. ''Because I'm young, there's the danger that I end up wearing stuff that makes me look older than I am. I have to be careful about my make-up too, and try to keep it subtle. If it's too heavy, you can put on years,'' she says.

If her working wardrobe has expanded, her waistline hasn't. Two years ago she lost a stone in a month following the Carol Vorderman Detox diet, and she's kept it off.

''It was brutal,'' she says, shuddering at the thought as we sip strong coffee in her pristine galley kitchen. ''Basically you stop eating and drinking. No alcohol, no caffeine, no wheat, just fruit, salads and seeds for a month. You couldn't stick to it for more than four weeks, but the great thing about it is that it helps you get out of all your old habits. It makes you aware of what's not good. For instance, I've stopped eating sandwiches at lunchtime because the wheat in the bread makes you lethargic and I can't afford to feel or look tired when I'm doing first minister's questions.

''Now if I've been overdoing it I just do a quick detox.''

Lined up neatly by the cooker is a set of Lady Claire MacDonald cookbooks, a birthday gift that looks relatively neglected compared to the well-thumbed copy of the Carol Vorderman Diet recipe book, which she describes as her ''bible''.

While it houses a groaning wine rack and ground coffee, Nicola's kitchen is bereft of any sign of food. It's predominantly stainless steel and is separated from her open-plan lounge by a funky glass brick wall which makes it seem like a sociable space, but even the built-in floor-to-ceiling fridge looks forlorn. She admits that she doesn't have much time for cooking or socialising. Peter, on the other hand, loves to cook for them both at his home.

''I like nothing better than to spend my nights in with a takeaway, a glass of wine and the telly,'' she says. She's only had one party since moving in. The life of a young Scottish politician is not, perhaps, as one might have imagined.

Nicola was born in Irvine, Ayrshire, and joined her local party at the age of 16. She studied law at the University of Glasgow and worked as a solicitor before becoming MSP for Glasgow Govan in 1999. Her two-bedroomed flat, which she bought 18 months ago, is only the second home she has owned.

The first was a Victorian tenement in the west end of Glasgow. In contrast this one is unashamedly contemporary, right down to its digital entry system, laminate flooring and magnolia-painted walls. Nicola hasn't decorated the flat and has no intentions of doing so.

Located in the middle of Glasgow, it feels like a cross between a student flat and an executive pad. A framed photograph of her beloved nephew Ethan, aged two, sits on the windowsill of her lounge in the furry embrace of a toy teddy bear while, nearby, lie her cordless digital telephone, mobile phone charger and Palm Pilot.

Nicola likes living here because the city centre has a vibrant, youthful feel and she enjoys being close to bars and restaurants. ''This is a young person's place and for now it suits me perfectly,'' she says. ''But I don't envisage living here forever.''

The flat is handily located for Queen Street station, and it is also convenient for constituency work in Glasgow, to which she devotes every Monday and Friday, as well as holding monthly surgeries in her Hope Street offices. Weekends are also occupied by constituency work and party politics. On Tuesdays, Wednesdays and Thursdays, however, when parliament sits, she commutes east to the capital. No two days are the same.

Nicola is a Cancerian - a star sign usually characterised by a strong domestic streak - but while her home is important to her, she says she's not obsessive about it. ''Having somewhere you can come back to and shut the door, close the curtains and chill is extremely important, but I'm not really a 'nesty' person,'' she says. ''I'm not into antiques, paintings or gardening - at least not yet. Maybe I'll grow into those things as I get older.''

The original paintings by the Scottish Colourists, operatic recordings and a library of first-editions beloved by Donald Dewar, the late first minister, are not her bag. On her living room walls are two small framed prints - one is a well-known Klimt and the other looks like a Modigliani nude, but she doesn't know who painted it originally. There's a small rack of CDs of Norah Jones, David Gray and Coldplay. Nicola is not a huge music fan.

''I like easy listening,'' she says. ''Stuff that's not too aggressive and that you can have on in the background while you get on with other things.''

What truly personalises her home is her collection of books. Rows of Ian Rankin hardbacks are jammed in alongside hefty political biographies on her many Ikea bookcases. Margaret Thatcher, Hillary and Bill Clinton, Tony Blair, Martin Bell, Denis Healey and Helena Kennedy are just a few of her favourite people.

''I have a very analytical mind, probably a result of my legal training,'' she says. ''Reading is one way to switch off. Rankin is my favourite author for relaxing. I'm serious by nature and have to work hard at my lighter side.'' She is aware that she is quite reserved and shy, and sometimes finds it difficult to open up to people.

''I'm pretty focused - I care deeply about what I'm doing. I take that side of my nature from my mum. My dad's more laid-back - he's quite jovial.''

Nicola might have chosen an extremely single-minded career, but she remains very close to her family, none of whom is a politician. Her parents are both in their 50s and she has a sister, Gillian, whom she says is very different from herself. ''As children she was blonde and blue-eyed and as an adult she's slim, tall and much more glam than me all round,'' she says, grinning ruefully.

Then her digital phone rings and she's being summonsed to appear live on BBC television. They're sending a car to collect her in five minutes. She swiftly arranges with her PA to go on directly from there to parliament, while rushing to fix her make-up. And, shock horror, she leaves behind our dirty coffee mugs to be washed later.

But then, that's the beauty of having your own front door.


Mobile phone

''I'd like to live without it but I can't - I don't ever turn it off, though if I'm in Chamber or in a meeting I'll put it on silent. I'm no technophile and only use it for calls and text messages, but the idea of doing my job without it is unimaginable.''

GHD (Good Hair Day) hair straighteners

''My hair used to be short before, but now that it's longer these have changed my life. They're so quick to use.''


''I'm trying to cut down to one or two strong cups in the morning only. I used to drink much more - six or seven cups a day - but Carol Vorderman's detox diet changed my life. I owe her a lot.''