Updated

A top lawmaker in Ukraine's pro-Russian parliamentary majority on Monday threatened President Viktor Yushchenko with impeachment if he calls new elections, again raising the stakes in the country's political crisis.

Taras Chornovil, a senior member of the Party of Regions, expressed his party's impatience over the political turmoil that has gripped Ukraine since March elections, in which the Party of Regions led by Viktor Yanukovych trounced the pro-Western reformers who had led the 2004 Orange Revolution.

The Party of Regions formed a majority coalition with the Socialists and Communists earlier this month, and nominated Yanukovych to be premier. But Yushchenko, who faces a Wednesday deadline to act on the nomination, dislikes the idea of working with his old opponent Yanukovych, whose fraud-marred presidential run in 2004 sparked the Orange Revolution.

CountryWatch: Ukraine

Chornovil warned that if Yushchenko calls new elections, he could be putting his own job at risk. Opinion polls suggest the Party of Regions could score a big win in a repeat election, and Chornovil said if the party managed to put together a 300-seat constitutional majority in a newly elected parliament, they would push for impeachment.

"We then, acting absolutely in line with the constitution, could announce the impeachment of the president, choose a new one or possibly transform the constitution so that the president is elected by parliament," he said.

Also Monday, Yushchenko met with Yanukovych, who has consistently taken a softer approach than some of his allies. Afterward, Yanukovych appeared more conciliatory, suggesting cooperation was still possible.

The president wants Yanukovych and the other party leaders to sign a national unity agreement — obliging Yanukovych to agree to the president's pro-Western and reformist policy goals. That could open the door for Yushchenko to put forward Yanukovych's candidacy for premier and for Yushchenko's party to join a new coalition.

"The doubts that society has today are about what road Ukraine will travel, whether there will be a 180-degree turn," Yushchenko told reporters after meeting with Yanukovych and other party leaders.

The accord in its draft form would commit the ex-Soviet republic to work toward joining NATO, the European Union and the World Trade Organization, and would safeguard Ukrainian as the sole national language.

Yanukovych campaigned in the March election on making Russian a state language, expanding power to Ukraine's regions and improving ties with Russia. He has called for cooperation with NATO, but has not endorsed membership.

Yanukovych's allies have complained that the accord is an attempt to get Yanukovych to disavow the election platform that brought his party to victory in March.

Yanukovych, however, suggested Monday that there was room to compromise. He said if more work was done on the document, it could be ready for signing Tuesday. He did not specify what changes would have to be made.