Known as the "Goddess of the Revolution" or as Ukraine's Joan of Arc, Yulia Tymoshenko's good looks and fiery speeches rarely leave people indifferent.
While her ally Viktor Yushchenko, the man who would be Ukraine's President, is a mild-mannered former banker, she is an outspoken MP who represents the radical wing of the protest. She says the things he can't afford to, mixes with the youth activists who occupied the centre of Kiev and talks an uncompromising game.
When parliament was almost over-run by opposition protesters last week, Mrs Tymoshenko tried to hold the doors open for them. If Mr Yushchenko is the good cop, she is the bad one. Her job - at least in the eyes of the activists - is to make sure that he holds his nerve and gives the people what they want.
Aged 44, she is fiercely ambitious and has made no secret of her desire to be Prime Minister in a Yushchenko administration.
Such a move would be controversial; she is despised by Russian nationalists and by Ukraine's discredited outgoing President, Leonid Kuchma, who threw her out of his government several years ago. She also has a reputation for being provocative, and for getting carried away by her own rhetoric. …