|Ukrainian MPs reject election result
Thousands of opposition supporters are camped outside the building
Ukraine's parliament has declared last Sunday's presidential poll invalid.
MPs backed a resolution saying the result of the run-off election was "at odds with the will of the people".
Prime Minister Viktor Yanukovych was declared the winner, but challenger Viktor Yushchenko has alleged fraud and refused to accept the result.
While the parliament cannot overturn the result, its views may carry weight with the supreme court, which meets on Monday to examine the fraud claims.
The parliament met in emergency session in the capital Kiev to discuss the crisis, and its proceedings were broadcast live on all national TV channels and to thousands of opposition protesters gathered outside the building.
A majority of MPs also passed a vote of no-confidence in the country's Central Elections Commission, which like the other vote was not legally binding.
Click here to see a regional breakdown of the official results
Before the vote, parliamentary speaker Volodymyr Lytvyn told MPs the most realistic solution would be to invalidate the poll.
"The logical issue to be raised is to declare the election politically invalid because the true will of the people is now impossible to establish," he said.
Dutch Foreign Minister Ben Bot - speaking for the European Union - said the "ideal outcome" would be to hold new elections.
Mr Bot told reporters in The Hague that a new poll should take place before the end of the year.
The EU's foreign policy chief, Javier Solana, who has been taking part in mediation efforts in Kiev, has described last Sunday's vote as fraudulent, adding that future relations with Ukraine depend on a democratic resolution.
Mr Yushchenko has called on thousands of his supporters to remain camped on the streets of Kiev until they achieve victory.
Rival protests have been staged in the eastern city of Donetsk by supporters of Mr Yanukovych. Many of them say the eastern region of Ukraine would secede rather than accept Mr Yushchenko as head of state.
POLITICAL CRISIS TIMELINE
21 Nov: Viktor Yanukovych declared winner of presidential run-off with 49.46% of the vote, compared to Mr Yushchenko's 46.61%
Independent observers subsequently declare the elections flawed, and thousands of people take to the streets
25 Nov: Supreme court suspends publication of election result until it considers the opposition's complaints
26 Nov: Mr Yanukovych and Mr Yushchenko hold talks with EU and Russian intermediaries, agree to seek peaceful solution
27 Nov: Parliament backs resolution declaring the election invalid, passes vote of no-confidence in the Central Elections Commission
Mr Yanukovych and Mr Yushchenko held talks on Friday, but agreed only to continue talking and to seek a peaceful solution.
Saturday's Ukrainian parliament meeting was its first gathering since a chaotic session earlier this week when Mr Yushchenko symbolically took an oath of office.
The rival candidates have set up a working group to discuss possible solutions which was also expected to meet on Saturday.
Independent observers, including some from the EU, have said the elections were flawed.
Moscow, however, has publicly backed Mr Yanukovych and says the dispute should be settled in the courts and not on the streets.
Mr Yushchenko's party wants the repeat vote to be held on 12 December, under the supervision of the Organisation of Security and Co-operation in Europe.
Mr Yanukovych has accused the opposition, which has been blocking access to government buildings, of attempting to stage a coup.
According to the official election result, the pro-Russian Mr Yanukovych won with 49.46% of the vote against Mr Yushchenko's 46.61%.
The supreme court suspended the presidential poll result on Thursday to consider the opposition's complaints.