Viktor Yanukovych was inaugurated as Ukraine's president Thursday, despite allegations by his rival of voter fraud, five years after massive protests of voter fraud thwarted his first bid at the office.

Ukraine's President Viktor Yanukovych holds a Bulava, a historical symbol of power, after taking oath in the parliament in Kiev, Ukraine, on Thursday. (Anastasia Sirotkina/Associated Press)

Yanukovych took the oath of office in the Verkhovna Rada, in Kiev. The Ukrainian parliament has been the scene of intense manoeuvring over the future of Yulia Tymoshenko, who aims to stay on as prime minister.

Yanukovych narrowly defeated Tymoshenko in presidential elections Feb. 7. Tymoshenko alleges vote fraud, but has dropped a court case on the claims.

The rivalry is not a new one.

Tymoshenko led the 2004 Orange Revolution protests that paved the way for a rerun of a presidential election in which Yanukovych had been declared winner. He lost the repeated vote to Viktor Yushchenko.

Yanukovych enters office with a shaky mandate, inheriting an economy crippled by the global financial crisis and a nation whose political loyalties are deeply divided.

He has broad support in the Russian-speaking east of the country, but in the Ukrainian-speaking west, he lost in virtually every region to Tymoshenko.

Her refusal to concede defeat and step down from the premiership threatens to prolong the kind of political wrangling that has paralyzed Ukraine's government for several years, deepening the financial crisis that shrank the economy by 15 per cent last year.

The parliament has not even been able to pass a budget for this year