Even in Manhattan’s toniest restaurants I have never felt as frumpy as I do walking into the elegant prewar mansion in Kiev that serves as the headquarters of the prime minister’s political party.

The long-haired, high-heeled young women striding through the corridors look like the sisters of the Ukrainian girls who crowd Western catwalks and seem to be dressed by the same couturiers.

Yet they are outshone by their boss, Yulia Tymoshenko, 47, the rabble-rousing heroine of Ukraine’s 2004 Orange Revolution, who sweeps into her office just after 6pm wearing a still-spotless cream-coloured suit and a smile that is just as fresh.

Tymoshenko, who began her second stint as prime minister last December, has had a dramatic career, making a fortune in the shadowy gas-trading business before going into government in the 1990s on a corruption-fighting agenda.

Her populist appeal was burnished by the Orange Revolution, when her fiery oratory helped rally Ukrainians behind pro-Western democrat Viktor Yushchenko’s ultimately successful bid for the presidency, in defiance of ballot-stuffing and media control by the pro-Russian incumbent regime.

The prime minister’s physical charm is potent. Up close she is dazzling. She opens our conversation with the practised politician’s trick of telling me something nice about myself, making me feel good while letting me know she is on top of her game.

Her gambit: She thanks me for teaching my daughters Ukrainian. I say they mostly hate me for it but her prime-ministerial endorsement will be useful ammunition in my domestic linguistic wars.

Ukraine itself has its own larger battles over language. Tymoshenko comes from Dnipropetrovsk in eastern Ukraine, an area often assumed to be largely Russian-speaking and keen on a closer relationship to the country known in Soviet days as their “big brother”.

Tymoshenko says the linguistic character of her region is changing. “When I joined the cabinet for the first time, I didn’t speak Ukrainian,” she recalls. “But after working in the government for two or three months, I began to.”

Like her fellow Orange Revolutionaries, she thinks language is an important marker of national identity — something you can’t take for granted in a state that has been around for less than two decades and has declared independence six times in the past 90 years.

While these subtle shifts between Slavic languages are a big topic in Kiev, they are obscure if you don’t happen to be Ukrainian. So I ask Tymoshenko about a more recognisable Ukrainian cultural symbol — her trademark coronet of braids.

At times, they have been a hot political issue. Once, challenged on whether the thick blonde plaits were her own, Tymoshenko dramatically unpinned and unbraided her hair in a Rapunzel-like display.

Tymoshenko cheerfully talks about the differences between men and women in a way that would shock most “we-are-all-equal” Western feminists.

Here is one of my favourite assertions: women are better at taking care of things — both kids and countries — than men: “You know how, when a family breaks up, in most instances, the child stays with the mother? She is the more reliable caretaker.

"It is the same with a country. I think that we are more reliable and we are more able to give up living a normal life to fulfil our responsibilities.”

She strikes a less balanced note — in fact, she doesn’t even try — when the conversation turns to Yushchenko, the Ukrainian president and her Orange Revolution ally.

The enmity between the two of them is the country’s great political drama — and its political tragedy. Together they faced down a corrupt government with authoritarian leanings that was openly backed by Russian president Vladimir Putin.

Today, despite their bickering, the Ukrainian economy is growing and the country is democratic and independent. But economic reforms are halting, given the growing aggression of neighbouring Russia.

The problem, she says, is that instead of attending to today’s problems, “others” are focused already on the “battle for the presidency in 2010”, when Ukraine will have its next election.

She tells me she has publicly disavowed any presidential ambitions for 2010 and is prepared to back Yushchenko if only he will let her — an assertion a little undermined as she lets slip: “I am certain I would be a better president.”

She can also claim credit — as she does — for the reprivatisation of Kryvorizhstal. This steel mill was sold off in the dying days of Ukraine’s ancien regime to a consortium of oligarchs including the then president’s son-in-law.

Tymoshenko led the drive to sell it a second time in an open auction. That sale — shown live on Ukrainian television and won by the Mittals, the London-based steel magnates — fetched $4.8 billion, more than any other privatisation in the entire former Soviet Union.

With apologies for the gloom, my parting question is a bleak one: could Ukraine revert to authoritarianism? “We are now immune to that illness,” she says decisively.

“No one will succeed in plundering our national identity or humiliating us or, God forbid, destroying us. For all the difficulties we face, we are moving forward.”