The Ukrainian president's party will retain its strong grip on power, according to returns Monday from a parliamentary election that was criticized by Western observers as unfair and biased against the opposition.

The West was paying close attention to Sunday's vote in the strategic ex-Soviet state of 46 million people, which lies between Russia and the European Union and serves as a key transit nation for Russian energy supplies to many EU countries.

Observers from the Organization for Security and Cooperation in Europe called the vote a setback to Ukraine's democratic and European aspirations. That assessment could lead to a further freeze in Kiev's ties with the West and push it closer to Russia.

Monitors said the election was marred by the absence of jailed former Prime Minister Yulia Tymoshenko and another opposition leader, the ruling party's use of government funding for the campaign and the skewed media coverage that favored the ruling party. While the voting process got positive ratings at most polling stations observed, the vote tallying lacked transparency, the group said.

"Considering the abuse of power and the excessive role of money in this election, democratic progress appears to have reversed in Ukraine," said Walburga Habsburg Douglas, the special coordinator who led the OSCE election observation mission. "We do not think that this election was fair because it was not level."

"Ukrainians deserved better from these elections," said Andreas Gross, the Head of the Parliamentary Assembly of the Council of Europe delegation. "Unfortunately, the great democratic potential of Ukrainian society was not realized in yesterday's vote."

The U.S. State Department characterized Ukraine's elections as "a step backwards from progress made during previous parliamentary elections and the 2010 presidential election, elections that had marked important steps forward for Ukraine's democracy."

In a statement, the State Department expressed concern over "the use of government resources to favor ruling party candidates, interference with media access, and harassment of opposition candidates."

The State Department also was "troubled by allegations of fraud and falsification in the voting process and tabulation, by the disparity between preliminary results from the Central Election Commission and parallel vote tabulations, and by the Central Election Commission's decision not to release precinct results."

President Viktor Yanukovych's Russia-friendly Party of Regions was leading in the count with 34 percent of the vote. Tymoshenko's pro-Western party was second with 23 percent, trailed by the Communists, Yanukovych's traditional allies, with 15 percent. Another liberal party, Udar (Punch), led by world boxing champion Vitali Klitschko had 13 percent and the far-right Svoboda (Freedom) party had 9 percent.

Yanukovych's party benefited strongly from an electoral change last year that replaced the strictly proportional electoral system with a mixed one, in which half of parliament's seats are elected based on party lists and the other half in individual races.

Despite a combined strong showing of opposition parties, Yanukovych's party was poised to retain its parliamentary majority as its candidates were expected to take the lead in individual races, benefitting from greater access to government funds and the opposition's fielding of multiple candidates.

Tymoshenko's party alleged widespread violations such as vote-buying and multiple voting. Tymoshenko, who was sentenced last year to seven years in prison for abuse of office in a trial condemned by the West as politically motivated, launched a hunger strike to protest the vote violations.

The Party of Regions defended Sunday's election, saying it reflected the people's will.

"We received a great credit of trust from the voters who said that we are moving down the right path," said Yanukovych adviser Hanna Herman.

The opposition tapped into the anger over Tymoshenko's jailing, the country's rampant corruption and a stagnant economy to make a strong showing in the proportional section of the vote. It remains to be seen whether Tymoshenko's group, Klitschko's party and the radical Svoboda can form a strong alliance.

"The Party of Regions won by the number of points, but the opposition scored a moral victory," said Kiev-based political expert Volodymyr Fesenko. "The monopoly on power will be harder to maintain."