Oligarch, street revolutionary, gas trader, fashion glamourpuss, prime minister: Ukraine's charismatic 'iron lady', Ms Yulia Tymoshenko, has had many incarnations. There might be yet another ahead.

After breaking once again with President Viktor Yushchenko - her former ally during Ukraine's Orange Revolution - Ms Tymoshenko, 47, is clearly manoeuvring herself to take his job.

If she did - and presidential elections are due in the next 18 months - she would become the only female head of state in a former Soviet republic.

To many observers, it would be the natural culmination of a career that started in obscurity, took her from great riches to prison and out again, and was utterly transformed during the biting winter nights of Ukraine's 2004 'revolution'.

Flamboyant and unpredictable but astute and utterly formidable to her adversaries, Ms Tymoshenko has effected an extraordinary transition from rich but reviled oligarch to the people's favourite.

Sustained by a carefully crafted image that is part Euro-chic and part Ukrainian folk princess, she now bestrides the Ukrainian political scene like a cross between Britain's first female prime minister Margaret Thatcher and actress Gwyneth Paltrow - prominent not just in television footage of Cabinet meetings, but also from fashion shoots and glossy magazines.

The symbiosis of power, femininity and brashness is perfectly summed up in her party's name:

BYuT (pronounced beaut, and short for Bloc Yulia Tymoshenko).

'She's bright, she's glamorous, she's intelligent, and she uses all three in skilful combination,' said Dr Andrew Wilson, an expert on Ukraine with the European Council on Foreign Relations. 'Her skill lies in her capacity for reinvention.'

Her latest reinvention has been quite startling. For years a fierce critic of Ukraine's menacing eastern neighbour, Russia, she has softened her rhetoric of late, refusing to criticise Russia for its Georgia escapade and popping up in Moscow to meet Russian leaders Dmitry Med-vedev and Vladimir Putin.

Mr Putin in particular appears bemused by her. When asked recently about perceptions that she was adopting a more Russia-friendly stance, he reportedly rolled his eyes and said: 'Heavens above. What have we come to now?'

'What Tymoshenko is trying to do is place herself astride the key divides in Ukrainian politics,' said Dr Wilson, noting that the country - the largest in Europe - is split down the middle between a pro-West, Ukrainian-nationalist western half and a russophone, ethnic Russian eastern half. 'It's probably a winning move in terms of domestic politics.'

Little is known of Ms Tymoshenko's early life. She was born in Dnipropetrovsk in eastern Ukraine during the post-Stalin thaw in November 1960 and studied cybernetic engineering at the city's university, where she met her husband Oleksandr. She was not yet 20 when her daughter Yevgeniya was born.

An undistinguished decade followed. Then suddenly, after a period spent running a moderately successful video rental chain, she emerged as the managing director of an oil trading company. This morphed into an energy trading com- pany, United Energy Systems of Ukraine (UESU), which was granted a monopoly for dealing with the vast volumes of gas pumped from Russia to Ukraine. It was a very lucrative business to be in.

Ms Tymoshenko is as much about glamour as political acumen. Always impeccably turned out, she keeps her hair in a traditional Ukrainian plait.

According to Polish academic and Ukraine expert Kataryna Wolczuk, 'she emerged with a personal fortune, the nickname Gas Princess, and an incomparable insight into the lucrative, corrupt and highly opaque gas-trading regime between Ukraine and Russia'.

By 1997, UESU was coming under scrutiny for the kind of murky accounting practices commonplace in the era of capitalistic free-for-all that swept parts of the former Soviet Union in the 1990s. But Ms Tymoshenko was already moving on. She had a seat in Parliament and, by the end of 1999, a government position as deputy prime minister. It didn't last long.

Ukraine was already descending in a whorl of intrigue and scandal that disfigured the last years of Leonid Kuchma's presidency. Ms Tymoshenko did not escape. She was fired in 2001 and charged with embezzlement. She even spent a month in prison until the charges were thrown out.

But the experience apparently triggered some kind of epiphany, because she quickly transformed herself from establishment oligarch into anti-government rebel-raiser - a street revolutionary at the head of a movement that grew until it camped out in downtown Kiev in front of the world's cameras toppling the old order.

Ukraine's Orange opposition felt it had been robbed of election victory. Ms Tymoshenko and Mr Yushchenko were the twin figureheads. They became known as the Beauty and the Beast in Western circles (she for her looks; he for the facial disfigurement brought on by dioxin poisoning that has never been explained properly).

Alas, there was no fairytale ending. Even at Mr Yushchenko's inauguration, the political marriage was turning sour.

'When did it all go wrong? Well, you could point to his inauguration, when his people believe that she organised her people to chant her name, which rather upstaged him,' said Dr Wilson.

She was fired in 2005, amid disagreement over what to do about the barons who had got rich quick under privatisation. Ms Tymoshenko wanted to go after them; Mr Yushchenko was more cautious. She, as ever, had her own theories as to why he had fired her. 'Let's be honest. Men have a hard time competing with women on a professional level,' she said at the time.

If that is true, it might be even truer in the post-Soviet political space, where male chauvinism flourishes and even women are not keen on female leaders. This makes Ms Tymoshenko's ascent even more remarkable.

As Dr Wolczuk put it: 'In a country notorious for its dismissive attitude towards women, Tymoshenko has seen off presidents and prime ministers, endured imprisonment and a probable assassination attempt to emerge as the most popular politician in the country.'

She will soon get another opportunity to test that popularity. Two weeks ago, after a second great schism opened up between the two Orange leaders, Mr Yushchenko finally dissolved Parliament and called snap elections, scheduled for Dec 7. Ms Tymoshenko was apoplectic. 'I believe this is nonsense, a crime against the country and an absolutely irresponsible political step,' she said.

And in a clever stunt that betrayed how media-savvy she is (she has a Facebook presence and other personal websites), she immediately invited Ukrainian television to film her trying to contact the President, the man whom she had helped sweep away the old order.

'This is a direct line which the President is supposed to pick up, whatever the circumstances,' she tells the camera. 'Unfortunately, for the last six months, it has worked in only one direction. When I call, I get no answer, just beeps.'

When the inexorable rise of Ms Tymoshenko is complete, few will refuse to take her calls.

This article was first published in The Sunday Times on Oct 19, 2008.