* Russia tightening controls on wine imports from Georgia
* Protests erupted after Russian lawmaker addressed MPs
* Protesters cheer ruling party changing electoral system (Writes through with details, background)
By Margarita Antidze and Maria Kiselyova
TBILISI/MOSCOW, June 24 (Reuters) - Russia on Monday served notice to ex-Soviet Georgia it faces painful consequences if anti-Russian protests are not brought under control, saying it was tightening controls on wine imports that bring Georgia millions of dollars in revenue each year.
Violent protests broke out in front of Georgia's parliament building last week after Russian lawmaker Sergei Gavrilov addressed the Georgian parliament from the speaker's chair, speaking in Russian.
That unleashed simmering resentment among many Georgians, who feel angry and humiliated that they have to maintain friendly ties with Moscow even though Russia briefly invaded their country in 2008 and still backs two breakaway regions of Georgia.
Georgia's president, French-born Salome Zurabishvili, blamed a "fifth column" loyal to Moscow for stirring up the trouble, while Kremlin spokesman Dmitry Peskov said on Monday that "Russophobic hysteria" was being artificially whipped up in Georgia.
The Russian state consumer watchdog, Rospotrebnadzor, said in a statement it was introducing the tougher checks on wine imports because of concerns about the quality of Georgian consignments. Kremlin spokesman Peskov denied any link to the political row.
But Moscow has in the past used bans on wine imports as a weapon in political disputes with Georgia. Russia has already suspended flights to Georgia by Russian airlines, hitting tourism, another major source of revenue for the Georgian economy.
When the protests first erupted on Thursday, police used tear gas and rubber bullets to prevent crowds of protesters from storming Georgia's parliament. Hundreds of people were injured, some seriously.
The protests have quickly developed into a double crisis: pitting Moscow against Tbilisi and pitting the protesters in Georgia against their own government, which has for years tried to smooth over differences with Moscow.
In a move that the anti-government protesters hailed as a victory, the ruling Georgian Dream party said that for the 2020 parliamentary election, the country would switch from a mixed electoral system to a proportional system, with no threshold for parties to get into parliament.
The switch was scheduled to happen anyway in 2024, but the protesters had been demanding that the change be brought forward. A proportional system is likely to make it harder for Georgian Dream to maintain its dominance in parliament without building a coalition.