MOSCOW — Russian President Boris N. Yeltsin warned Friday that political parties campaigning on television against his proposed constitution will lose their right to broadcast free pre-election advertising.
"The free time will be taken back from you if you deviate from your subject, and your subject is your platform," he told leaders of 13 parties summoned to the Kremlin. "I ask you not to touch on the constitution."
Except for a ban on six extremist movements and the newspapers that back them, Yeltsin's statement was his firmest step to limit free debate before the Dec. 12 elections, in which voters will choose a new two-chamber Parliament and vote on a new constitution.
The warning was a sign that Yeltsin is far more concerned about the fate of the proposed charter, which would usher in a post-Soviet legal order and vastly strengthen presidential power, than the makeup of Parliament itself.
A majority vote for the constitution would allow Yeltsin to advance his free-market reforms whether or not his allies dominate the 450-seat Duma and 178-seat Federation Council. Drafted in secret without public debate, the new charter would give the president the power to dissolve Parliament and call new elections, for example, if it rejects his nominees for prime minister three times in a row.
Four parties favoring Yeltsin's reforms are in the race. But they are not assured of winning a majority of seats and, even if they do, might not work together on all issues.
Communist and nationalist parties, which led the Soviet-era Congress of People's Deputies that Yeltsin dissolved this fall, are waging strong campaigns.
Communist Party leader Gennady A. Zyuganov is running for the Duma and also campaigning for a "no" vote on the proposed charter, calling it a Napoleonic code for one-man dictatorship. All parties have criticized the draft, but most favor its adoption by voters, to be followed by amendments by the new Parliament.
"I don't see why it cannot be openly and publicly discussed, as is the practice in any country about to adopt a constitution," Zyuganov said Friday after attending the Kremlin meeting and rejecting the effort to limit the pre-election debate.
"Yeltsin's constitution would destroy the separation of powers, allow free trading of land," he said. "We are not going to discard our views in the next steps of our campaign."
Stanislav S. Govorukhin, a popular film director who is running for Parliament from the Democratic Party of Russia, apparently provoked the president's warning by declaring on television Wednesday night that the draft constitution was stained by the blood spilled Oct. 4, the day Yeltsin sent army tanks to crush the old Parliament.
"Even before its birth, this constitution has committed an evil deed," Govorukhin said. "On a moral scale, it has thrown our society back into the times of totalitarianism."
Yeltsin's threatened restrictions apparently apply only to the one hour of free television time given each party to use in segments between this week and the election. That time is crucial because of television's reach across Russia's 11 time zones and the cost--$700 per minute--of paid political advertising.
But Anatoly Sliva, deputy head of the president's State Legal Department, suggested that the ban on criticism of the constitution was broader.
In a statement read on television, Sliva argued that because the Duma and Federation Council are new legislative bodies enshrined in Yeltsin's constitutional draft, then any party or candidate opposing that draft in any form automatically rules itself off the ballot.
That logic underscores the biggest uncertainty of the campaign: What happens if voters reject the constitution? Many candidates assume that the new Parliament would convene anyway, as a constitutional convention, and write a basic law from scratch, but that is not clearly spelled out.
Worried by such a scenario, presidential Chief of Staff Sergei A. Filatov told regional leaders in the Kremlin last week that Yeltsin's entire 1994 program would be ruined. "We will be in big trouble if we do not approve this constitution," he warned.
Sergei Loiko of The Times' Moscow Bureau contributed to this report.