Defying vehement opposition, Ukraine's pro-government lawmakers on Tuesday gave tentative approval to a bill that would allow the use of Russian in official settings alongside Ukrainian in some regions.

Hundreds of angry opponents of the law clashed with helmeted riot police outside parliament and on Kiev's main square as tensions soared ahead of the Euro2012 football championship that kicks off here on Friday and a hotly contested parliamentary election in October.

Allowing or banning the use of Russian is one of the most divisive topics in post-Soviet Ukraine, split into the Ukrainian-speaking west yearning to shake off Russian influence and integrate with the West and the Russian-speaking east and south eager to maintain Ukraine's historic ties to Moscow. The previous debate of the bill in parliament late last month ended in a fight that left one lawmaker hospitalized.

Members of pro-Western opposition parties oppose the bill that would make Russian a de facto second state language, saying it would essentially crush the Ukrainian tongue and Ukraine's independence from Moscow. They say that President Viktor Yanukovych is trying to win back voter support ahead of the parliamentary election to reverse the decline of his popularity.

Yanukovych loyalists who draw their support from the Russian-speaking east and south of Ukraine passed the bill in the first of two readings Tuesday morning, saying it will give millions of Russian speakers in Ukraine the right to use the tongue of their choice. It was unclear when the final discussion of the bill would take place.

"This bill fully corresponds to Ukraine's European aspirations and European obligations," said Vadym Kolesnichenko, who co-wrote the bill.

But members of the pro-Western opposition argue that the bill will stem the development of Ukrainian by creating no incentive for millions of Ukrainians to learn and use it. They also say it will pull Ukraine back into the Russian sphere of influence and hamper efforts to build closer political and economic ties with the European Union.

Opposition members said they would continue their protests during Euro 2012 and vowed that the bill will never become law

"The law on a second state language in Ukraine will not exist," said opposition leader Arseniy Yatsenyuk. "We lost the battle, but we will win the war."

Prime Minister Yulia Tymoshenko, who is serving a seven-year jail sentences on charges denounced as politically motivated by the West, vowed in a statement on her web site that the law will be reversed.

"It isn't a peculiar wish of mine from behind bars, it's a guarantee!" Tymoshenko wrote.