The Ukrainian parliament backed a controversial law giving higher status to the Russian language – a move that prompted fights inside the chamber and protests on the streets of the former Soviet republic.
One MP suffered a broken rib from the mêlée in which police used tear gas against people demonstrating in the capital, Kiev.
The law proposed by President Viktor Yanukovych's Party of Regions now just needs his signature to come into force. But the issue has reopened deep wounds in the country, which is split between the Russian-speaking East and the Ukrainian-speaking West.
The measure, allowing Russian to be used as a "regional language" in predominantly Russian-speaking areas, was passed in a surprise move on Tuesday night, just moments after it was proposed by a pro-Yanukovych MP, giving opponents little time to cast their votes and prompting scuffles in parliament and on the streets.
Among those protesting yesterday was Vitaly Klitschko, the world heavyweight boxing champion who now runs his own political party. His arm was cut and he was tear-gassed by police outside a government building where Mr Yanukovych had been due to give a speech summing up a successful hosting of the Euro 2012 football tournament.
Ukraine is divided almost in half when it comes to how many people speak mainly Ukrainian and how many are mostly Russian speakers. Volodymyr Kulyk, of the Institute of Political and Ethnic Studies in Kiev, said that while almost everyone understood Ukrainian, and it was the only official state language, it was almost never heard in eastern cities such as Donetsk, or in the southern region of Crimea.
The Deputy Prime Minister, Boris Kolesnikov, told The Independent last week that the proposal was "in line with all European norms and simply a matter of improving democracy". But opponents said it could be the death knell for the Ukrainian language, because people would take the easier route of speaking Russian.
"State officialdom is currently the only sphere in which many people come into contact with Ukrainian, and if we take that away then the language is in trouble," Mr Kulyk said, adding that the survival of the language – and even the country –could be at stake. "Given the pressures on Ukraine from Moscow to integrate, if we lose our language and identity, after some time it might be impossible to keep the two countries separate." Moscow has long called for Ukraine to recognise Russian as its second language.
Analysts say Mr Yanukovych's party has tabled the bill to shore up support in his voter base in the east ahead of October's elections. The President must now decide whether or not to sign the controversial law into the statute book and risk a further deterioration in Ukraine's fractious political scene.
Yulia Tymoshenko, one of the leaders of the Orange Revolution in 2004, was jailed for seven years last year on charges that many believe were a matter of political revenge by Mr Yanukovych.
He narrowly defeated her in the presidential election two years ago.