"We understood that we are a team," she said at that time.

It's an assertion Yushchenko disputes -- a clash of views that has defined this partnership since they overturned a Soviet-style leadership in the 2004 "Orange Revolution" and vowed a modern, Western future for Ukraine's 47 million people.

Then they stood shoulder-to-shoulder -- her revolutionary speeches firing up crowd after crowd, his more academic approach comforting those who feared she was reckless in her pursuit of power.

Now barely on speaking terms, their bickering over policy and outlook could force the former Soviet republic into the third parliamentary election in as many years.

But was their partnership only ever a marriage of convenience?

In 1999, the tough former businesswoman, dubbed the gas princess because of her success in the cut-throat world of post-Soviet energy dealings, became deputy prime minister for energy in Yushchenko's government. She was dropped in 2001 and former President Leonid Kuchma launched a corruption case against her.

Some Ukrainian media say it was Yushchenko, fearful for his political future, who agreed to let her go, opening the way for corruption charges she says were fabricated by Kuchma.

Since then, many think the pair's jealousies and mistrust of each other have made them squander the chance to steady Ukraine on a path towards Western integration and reform.

She lasted less than a year as Yushchenko's first prime minister, sacked after they fell out over policy, particularly her calls for a broad review of 1990s privatisations.

Now sporting her trademark peasant braid, she is back as prime minister. Many analysts say Yushchenko is desperate to challenge her lead in the opinion polls, which suggest she would win a presidential election and gain seats in any vote for parliament.

Accusing her of dangerous populism that threatens to wreck the economy, Yushchenko has come out fighting. His office has accused her of being a traitor for not openly supporting Georgia after its brief war with Russia over South Ossetia.

He says she has driven the economy to the brink, with inflation reaching a record 30 percent earlier this year. His office says she is selling Ukraine out to the Russians to ensure Moscow's support for the election.

But she denies all charges and is trying to convince her doubters that she can be pragmatic.

She has called for Yushchenko's Our Ukraine party to return to the ruling coalition after he said the government had collapsed -- a departure from her usual fiery stance which is bound to antagonise Yushchenko even further.

This battle of wills looks set to run.

Western support for the opposition -- open and behind the scenes --  helped many people overcome fear of Soviet-style reprisals to stand for days outside Georgia's parliament in 2003 or to pitch orange tents on Kiev's main thoroughfare in late 2004, providing a lasting image of "people power" overthrowing a stale leadership.

Washington, or at least organisations with close political ties with the Bush administration, had courted opposition parties in both countries, coaching in the methods of democracy or securing "regime-change" as they sought to end the rules of President Leonid Kuchma and Georgian leader Eduard Shevardnadze. 

But the new leaders, and their teams, soon found that the attentions of an adoring West didn't last for long. Ukraine's team of President Viktor Yushchenko and Prime Minister Yulia Tymoshenko soon fell apart.                                                                                                                                                                             The West grew tired of the constant bickering of the Ukrainian leaders, unable to agree on almost any policy, while a resurgent pro-Russian Viktor Yanukovich, who lost a rerun of the presidential election, encouraged unity in his own party and rose in popularity.

In Georgia, Saakashvili cracked down on post-election protests last year and now some blame him for taking Tbilisi into a war it could never win.  

The war in South Ossetia has frightened Ukraine. Yushchenko was quick to turn to the United States, saying he considered "U.S. support for Ukraine to be very important".

But has the West given up? Ukraine and Georgia have been promised membership of NATO one day but the alliance decided at a summit in April not to give them a road map to membership.

Tomas Valasek, director of foreign policy and defence at the Centre for European Reform, said Georgia could be ruled out of NATO membership for the time being. "There will be allies who will say that this government is not creating stability, if anything it has done the exact opposite ... you don't want an ally in NATO that has a propensity to act the way that Saakashvili did."

 But it could go either way for Ukraine.

"You could argue that no one will go to war over Ukraine, and then it will be difficult to invite Ukraine into NATO," Valasek said. "Or the allies might decide this -- that it is important that we prevent Russia acting irresponsibly in the neighbourhood, and it is important to send a message to say we will not be discouraged by what happened in Georgia."