The reunited parties of Ukraine' tumultuous Orange Revolution had a strong combined lead Tuesday in the vote count from this weekend's parliamentary elections, increasing the possibility the fractious parties could hammer together a ruling majority.

Hopes for co-majority by President Viktor Yushchenko and the charismatic opposition leader Yulia Tymoshenko were still tenuous, though, after a better-than-expected performance of smaller parties that could side with their rival.

Yushchenko and Tymoshenko declared themselves winners of Sunday's vote and put forward plans for forming a new Cabinet. But Prime Minister Viktor Yanukovych, whom they want to unseat, also claimed victory.

The uncertainty raised fears that the ex-Soviet republic could face a replay of the political tug-of-war that Yushchenko wanted to end by agreeing to the early vote.

With just over 94 percent of the ballots counted, Yanukovych's Party of Regions was leading with 34.2 percent, while Tymoshenko's bloc followed with 30.8 percent. Yushchenko's party had 14.3 percent.

A handful of the Verkhovna Rada's 450 seats could go to three minor parties that performed better than expected. Two seem certain to join Yanukovych's party, though one, the Socialists, is still on the brink of a 3-percent threshold of getting into parliament.

The third party, whose affiliation is less clear, could emerge as a kingmaker by joining either an Orange alliance or Yanukovych in a fragile coalition.

Another important issue is that Yushchenko and Tymoshenko — heroes of the popular protests that overturned the rigged 2004 presidential election — have long been estranged and there is no guarantee they could patch up their differences if they should win a combined majority.

Any party or coalition requires an absolute majority of at least 226 seats to govern.

Tymoshenko was quick to celebrate her victory, but stayed out of the public eye Monday as the vote count showed that Yanukovych could potentially rival the Orange team if he lures the smaller parties over to his side.

Yanukovych said the Orange parties were too quick to claim victory and that the election gave him "carte blanche" to stay at the helm.

"We won and I am convinced that we will again form a government of national trust and unity," he told thousands of supporters on Monday who gathered at Kiev's Independence Square, the center of the 2004 mass protests.

He added that he was ready to share some power with other parties: "We are capable of forming a broad coalition headed by the Party of Regions."

Adding to the uncertainty was the slow count of results from Russian-speaking eastern and southern regions, where Yanukovych traditionally draws support, prompting some to suspect fraud.

Yushchenko ordered an investigation, warning that "those forces who aspire to get into parliament with the help of machinations" will be punished.

After the initial vote in 2004 that was won by Yanukovych, Yushchenko and the charismatic, golden-tressed Tymoshenko inspired thousands of protesters to protest. Yushchenko won a court-ordered rerun and named Tymoshenko his prime minister, replacing Yanukovych, the prime minister who was openly backed by the Kremlin.

But the Yushchenko and Tymoshenko fell out and Tymoshenko was fired after just seven months. Infighting opened the way for Yanukovych to return as prime minister last year.

Even if the Orange team can form a majority coalition, the alliance may be shaky.

The two parties have already agreed on how to divide up Cabinet portfolios — a deal that would make Tymoshenko premier.

Tymoshenko reaffirmed on Monday her ambitions to run for president in 2009, underlining a key obstacle in forming a lasting coalition. Yushchenko has not said whether he would seek another presidential term, but he is widely expected to run.

"Two leaders aiming for the same presidential seat make the Orange coalition quite unstable," said Mykhailo Pohrebinsky, an independent political analyst.

Yanukovych has hinted his party could protest against a fraudulent vote — a potential role reversal from 2004. But the Organization for Security and Cooperation in Europe gave a largely favorable assessment of Sunday's vote.

The election was conducted "mostly in line with international commitments and standards for democratic elections," the OSCE observer mission said.