Ukraine's constitutional court has ruled that President Leonid Kuchma can run for a third term next year.
Mr Kuchma has no plans yet to run for re-election
The 1996 constitution says a president can serve only two terms but the court said Mr Kuchma's first term, which began in 1994, did not count.
Mr Kuchma has said he has no plans to run again but the opposition accuses him of seeking to cling to power.
Last week the parliament approved moves to have the president elected by parliament from 2006 onwards.
The court's decision angered the opposition, which accuses Mr Kuchma of running a corrupt and autocratic government.
Mykola Katerynchuk of the Our Ukraine party said opposition politicians would consider organising mass protests in mid-January.
"The people must decide whether
they want Kuchma in power for an indefinite time to come,"
The opposition has tried in the past to topple Mr Kuchma through mass demonstrations - notably after accusing him of involvement in the death of opposition journalist Georgiy Gongadze in 2000 - but without success.
Mr Kuchma's spokeswoman, Oksana Kosareva, was quoted by AP news agency as saying the president's plans not to stand for re-election had not "yet" changed.
Judge Volodymyr Voznyuk quoted the court's ruling to reporters.
"Limits envisaged by the constitution are relevant to a person who occupied the presidential post for two terms and was given the powers in line with the existing constitution," he said.
"It means the person who was first elected under the current constitution in 1999 has a right to turn again the presidential elections in 2004."
Mr Kuchma, 65, is currently on a trip to the German spa town of Baden-Baden after undergoing abdominal surgery last month.
A recent opinion poll by the Democratic Initiatives Foundation
showed that only 7.6% of Ukrainians "trust" Kuchma compared
with nearly 60% who "do not trust" him.
The proposed constitutional amendments allowing the president being elected by parliament must pass a second vote requiring a two-thirds majority before becoming law.
Last week they won the support of 276 out of 450 deputies.
A date for the final vote has not yet been scheduled.