Thousands of people protested negotiations between the Georgian government and Russia's state-owned energy giant, Gazprom, Sunday in the Georgian capital, Tbilisi.
The demonstrators formed a nearly 7-kilometer (4-mile) human chain, stretching from the Russian Embassy to the government headquarters.
The protesters said they feared buying gas from Gazprom would make Georgia dependent on Russia.
The rally was organized by former President Mikheil Saakashvili's pro-Western United National Movement party (UNM), which accuses Moscow of using Gazprom in a bid to prevent Georgia from forging closer ties with the West.
The government said Friday that it had signed a deal with neighboring Azerbaijan to increase gas supplies enough to fully cover Georgian demand.
However, opposition leader in parliament David Bakradze said Georgian officials "tried to deceive us by saying it was not technically possible to increase gas supplies from Azerbaijan."
"The Georgian society will not allow this government to undermine the country's energy security," the senior UNM lawmaker said.
Energy Minister Kakha Kaladze said Saturday that officials had abandoned the plan to buy natural gas from Russia after it had secured a deal with Azerbaijan to purchase additional volumes of gas.
Previously, Kaladze had justified the negotiations with Gazprom by saying Azerbaijan didn't have the technical ability to supply more gas. But he said those problems had been overcome.
Bakradze said protesters had "forced the government to do everything possible to receive additional fuel from Azerbaijan. ... We will not allow Georgia to be under Russia's control."
Russia and Georgia fought a brief war in August 2008 over the two Moscow-backed breakaway regions of Abkhazia and South Ossetia.
Some material for this report came from RFE/RL, AP and AFP.