Yulia Tymoshenko cancelled news conferences twice on Monday
By Richard Galpin
BBC News, Kiev
She has not said it herself so far but Ukrainian Prime Minister Yulia Tymoshenko seems to be preparing the ground to challenge the results of Sunday's presidential election.
The anticipated move comes despite the Central Election Commission (CEC) and international observers saying they have found no evidence of significant fraud and that both voting and counting were fair.
Members of the Tymoshenko bloc in the Ukrainian parliament have been lining up today to question the validity of the result in more than 1,000 polling stations out of a total of more than 30,000 across the country.
"We will appeal in the courts not against the quality of the election, which was evaluated by the international observers, but against the quality of counting the ballots," said Andriy Shkil.
"Believe me, public opinion [in Ukraine] and European opinion will coincide with ours when we prove this in the courts."
Other party members say the number of falsified votes is more than the margin of approximately 900,000 by which Mr Yanukovych won the election.
That means the entire election result may eventually be called into question by Mrs Tymoshenko.
So a battle looms.
The smooth transition of power that European election observers said should be a priority for political leaders here is looking less and less likely.
On the square outside the CEC, the number of Yanukovych supporters arriving from around the country is growing.
On Tuesday morning, Sergei Tyagni, a local organiser for Mr Yanukovych's Regions Party, was on stage telling the crowd they would stay on the square "until the end" in order to defend their victory.
"Yes, as a party member I will call for other members and supporters to come out on to the streets, to protest and unite [if the election results are challenged in court]," he told me.
"But the courts will not go in her favour."
It is all adding to a growing sense of uncertainty in Ukraine especially as some analysts believe the legal action by Mrs Tymoshenko's party is just part of her plan.
"To make this [legal action] more weighty, she will try to organise protests and I don't exclude the possibility of there being attempts to occupy official buildings," said Andriy Kulykov, a political journalist and well-known TV talk show host.
"I have no doubt there will be quite a havoc after the election and there's probably a plan to bring the situation to the boiling point before saying there's a need for a truce... and then they will be able to settle the arguments between them."
In the midst of a deep economic crisis, this is the last thing Ukraine needs as a result of the election.