Incumbent President Viktor Yushchenko said on Tuesday he is confident of victory in the January 17 election.
"I have no doubt - I repeat, no doubt - that I will be victorious," he told a news conference.
The president said his reelection was "the only realistic way of standing up for Ukraine and Ukrainians" and continuing the policies he had pursued for the past five years.
He warned that Ukraine was staring dictatorship in the face, with the greatest threat coming from Prime Minister Yulia Tymoshenko.
Yushchenko said the changes to the constitution made in 2006 had unsettled the system of government in Ukraine and now all the power was concentrated in the hands of the head of government.
Opinion polls point to Viktor Yanukovych, Yushchenko's opponent in the 2004 race, as the leading contender with ratings 10% higher than those of his closest rival Tymoshenko, who supported Yushchenko in 2004 but has since become the president's bitter rival.
According to some polls, Yushchenko's rating numbers are below 3%, but his campaign office earlier suggested those numbers were misleading and his support was being deliberately underreported.
"If you keep repeating that the president's rating numbers are 2%, even his supporters may lose the motivation to vote for him," said Maryna Stavniychuk, deputy head of the president's secretariat.
KIEV, January 12 (RIA Novosti)
