The two main rivals of Ukrainian President Viktor Yushchenko appear to have made huge gains in the country's parliamentary elections. Exit polls suggest the pro-Russian party of former PM Viktor Yanukovich, the man who lost the 2004 presidential election, will be the biggest party.

The president's party appears to have been beaten into third place by his former ally Yulia Tymoshenko. If confirmed, the results would be a humiliating blow for Mr Yushchenko. Counting of ballots is not expected to be completed until Tuesday. The BBC's Helen Fawkes in Kiev says a victory for Mr Yanukovych - who was written off a year ago - would be a dramatic comeback.

He was declared the winner of the presidential election in November 2004, but allegations of widespread vote-rigging sent hundreds of thousands of Ukrainians out on to the streets to demand change. In what became known as the Orange Revolution, the election result was later overturned and Mr Yushchenko went on to win a re-run. This is the first election since then and Mr Yushchenko's popularity has plunged.

Exit polls suggest the party of Mr Yanukovych has taken about a third of the vote. "Today's victory is a revelatory moment for both myself and the Party of Regions," he said. "It has shown that despite everything, the people have managed to show their great support of our political force." Mr Yanukovych said he would support ties with the European Union, as well as mending Ukraine's relationship with Moscow.

Fragile coalition

A recovery for Mr Yushchenko would still be possible if the former Orange allies can form a partnership. The BBC's regional editor Olexiy Solohubenko says if personal ambitions are set aside, Mr Yushchenko's party may be able to form a parliamentary majority - and the new government.

Mrs Tymoshenko - whose party looks to have come in second place - has said that as part of any agreement she must be made the prime minister. "We said repeatedly that this election was about choosing the prime minister and now the people have spoken," she said.

Yulia Tymoshenko was previously fired from the post of PM

She has also vowed to cancel a controversial gas deal Ukraine signed with Russia. Both of these proposals would be difficult for Mr Yushchenko to accept but he has been left with few options, our Kiev correspondent says.