The vote, which bans any attempt to dissolve the country's leglisature through a plebiscite, cast a shadow over frantic efforts to defuse a potentially explosive confrontation between President Yeltsin and the Congress.
Russia's current political crisis, rooted in a constitutional impasse over the division of power between the executive and legislature, is the country's deepest since the abortive coup in August last year.
One one side stands the Congress, elected in 1990 and denounced by reformers as a bastion of reactionary hardliners. On the other is President Yeltsin and fellow champions of free-market reform, whom conservative legislators accuse of trying to amass autocratic powers and ride rough- shod over the constitution.
Enraged by legislators' refusal to confirm Yegor Gaidar, a 36- year-old economist at the centre of Russia's reform drive, as Prime Minister, President Yeltsin on Thursday lashed out at what he called a 'creeping coup', and vowed to ask the country to decide whether the Congress should be dissolved.
Yesterday, though, politicians on both sides appealed for calm, and promised to settle their dispute through constitutional means. 'Both sides have made compromises. The path towards confrontation is unacceptable to society,' said the head of the Foreign Affairs Committee, Yevgeny Ambartsumov, after a meeting with President Yeltsin yesterday.
The main hope for a settlement lay in talks late yesterday between President Yeltsin and his principal adversary, the Congress Speaker, Ruslan Khasbulatov. The two men met for about an hour at the Kremlin with the head of Russia's Constitutional Court, Valery Zorkin. Further talks were scheduled for today. A spokesman for Mr Khasbulatov described the talks as 'constructive enough' but gave no hint of a breakthrough.
Several legislators had suggested earlier that President Yeltsin was ready to postpone his plans for a referendum and ditch one of his closest aides, Gennady Burbulis. In return, they said, Congress would allow Yegor Gaidar to stay on as acting Prime Minister for another six months. A presidential spokesman, however, denied any such deal had been made. President Yeltsin said yesterday that he would offer no candidate for head of government other than Mr Gaidar, a Yeltsin spokesman said.
Clearly worried about a long struggle, the Congress yesterday moved to counter President Yeltsin's principal asset - his personal popularity - by placing strict limits on the use of referendums. Despite a year of economic 'shock therapy' that has eroded support for radical free-market reform, President Yeltsin remains the country's most popular political figure and could well win a ballot-box showdown.
President Yeltsin told a raucous session of Congress on Thursday that he would call a referendum in January. He promised to resign if he lost, and dissolve Congress and hold new elections if he won.
Yesterday amendement to the referendum law - rejected on the first vote but later approved - restricts President Yeltsin's already limited room for manoeuvre and threatened further to sour talks with Mr Khasbulatov.
President Yeltsin and Mr Khasbulatov, who were close allies until a year ago, are the main actors in the struggle to determine where ultimate power in Russia should lie: in a strong president or a powerful parliament.
In interviews published yesterday, Mr Khasbulatov denounced Mr Yeltsin as an autocrat and vowed: 'We will not allow any dictator or tsar.'Reuse content