Lawmakers convened in parliament Tuesday in hopes of striking a deal that would secure a fair presidential vote at the end of the month, and opposition protesters appeared to grow restless with the prolonged political crisis.

An initial agreement Monday between opposition leader Viktor Yushchenko's (search) camp and Prime Minister Viktor Yanukovych's (search) supporters called for simultaneous passage of two issues by parliament.

One issue was opposition-demanded electoral changes to prevent fraud in the Dec. 26 presidential election — a rerun of the Nov. 21 runoff balloting. The other was government-demanded constitutional reform that would trim presidential powers.

But the deal appeared in jeopardy early Tuesday after late-night European-mediated talks between Yushchenko, Yanukovych and President Leonid Kuchma (search).

Polish President Aleksander Kwasniewski (search), who helped mediate the talks, said Tuesday the agreement marked only minimal progress, and that the differences between the sides remained "enormous." Speaking to reporters in Kiev, Kwasniewski said the candidates did little more than define their differences in six hours of talks.

As the search for a compromise continued in Kiev, Russian President Vladimir Putin (search) warned against foreign interference in the new ballot but pledged that Russia would abide by the vote results.

Secretary of State Colin Powell, in Bulgaria for a meeting of the Organization for Security and Cooperation in Europe (search), rejected Putin's accusations of Western interference.

"What we have seen is not anyone interfering in democracy," he said Tuesday. "What we have seen is the international community coming together to support democracy."

A somber Kuchma told reporters the parties had failed to agree on the constitutional reform and on the opposition's push for Yanukovych's resignation, which is being brought about because of last week's parliamentary no-confidence vote in the government.

He expressed hope that a conciliatory commission meeting Tuesday would "achieve success and solve the issues that we failed to solve."

In the agreement, Kuchma pledged to reshuffle the Central Election Commission — a key opposition demand — and emphasized the need to pass electoral changes to ensure "a fair and transparent vote."

However, the lack of consensus on the constitutional changes made the implementation of those pledges unlikely. A similar compromise deal fell apart Saturday.

Yushchenko has criticized the proposed constitutional changes, which would turn some presidential powers over to parliament. He has said Kuchma and his allies, fearing his victory, want to weaken the presidency.

Mikhail Pogrebinsky, an analyst with the Institute of Political and Conflict Studies who has close ties to Kuchma, said he expected Kuchma to cave in to the opposition's demand to fire Yanukovych.

"Kuchma is coming under enormous pressure, and he has been slowly taking a step back every day," Pogrebinsky said. "I fully expect this next concession today."

He said that if Kuchma agrees to fire Yanukovych, Yushchenko will be left with little choice but to support the political reform to hand some presidential powers to parliament.

Kuchma refused again Tuesday to fire Yanukovych, but said he would appoint an acting prime minister to handle his duties during the new presidential campaign, said pro-government lawmaker Mykola Hapochka. "Kuchma is ready to approve Yanukovych's leave of absence ... but Kuchma is not ready to sign his resignation," Hapochka said.

Yushchenko is under fire from Socialist Party leader Oleksandr Moroz to support the changes. Moroz, who came in third in the first round of voting on Oct. 31, threw his support behind Yushchenko in the second round.

"Yushchenko knows that without Moroz, he might not win," Pogrebinsky said.

Yushchenko backers in their third-straight week of protests in a sprawling tent camp in downtown Kiev barricaded the entrance to the Cabinet building, determined not to let "a single bureaucrat enter," said Adam Yanakievych from Kiev.

The opposition leader has urged his supporters to remain in the tent camp and continue blockading official buildings until Kuchma fires Yanukovych and stops stalling changes in the electoral system.