The Ukrainian parliament Tuesday backed a controversial bill that the opposition fears would make Russian the country's de facto second national language as several thousand protesters rallied in the city centre.
The highly polarising bill increasing the role of the Russian language in the linguistically divided country was passed on its first reading, with 234 lawmakers in the 450-strong Verkhovna Rada voting in favour and two against.
Language and history are the two main fault lines running through the ex-Soviet country and dividing it into the Kremlin-friendly Russian-speaking east and the more nationalistic Ukrainian-speaking west.
President Viktor Yanukovych, who draws support from the east and won elections in 2010 on pledges to improve ties with Moscow, has promised to give Russian a more prominent role in Ukraine.
Sponsored by Yanukovych's supporters, the bill expands the use of minority languages but stops short of granting Russian the status of an official second language.
The opposition says the bill effectively makes Russian the second state language.
The protests underlined the political turbulence in Ukraine as it prepares to host the Euro 2012 football starting this week amid strong Western criticism of its treatment of jailed opposition leader Yulia Tymoshenko.
Around 3,000 people including Vitali Klitschko, a boxing star and leader of an opposition party, rallied outside the parliament building to protest the bill, while another 3,000 protesters turned up to back the initiative.
"Shame!" chanted the protesters brandishing placards that read: "One State, One Language," "Invaders and Russifiers -- Get Out of Ukraine, and "Stop Dividing Ukraine."
"I speak Ukrainian, Russian, German and English," Klitschko said at the protest. "But as a Ukrainian, I am sure that we should have only one state language -- Ukrainian."
Brief scuffles broke out between police and opposition activists at the rally as the two sides used tear gas against each other, an AFP photographer reported from the scene.
The demonstrators in favour of the bill -- who were separated from their opponents by metal barricades -- demanded that Russian be given the status of an official language.
"There Are 16 Million of Us and We Speak Russian" and "Two Languages, One Country" read their slogans.
In late May, a parliament debate on the use of the Russian language descended into chaos, with dozens of lawmakers fighting over the bill.