Ukraine's parliament approved a law on Thursday that grants special status to the Ukrainian language and makes it mandatory for public sector workers, despite opposition from the country's large Russian-speaking minority who feel it is discriminatory.
The move, which obliges all citizens to know the Ukrainian language and makes it a mandatory requirement for civil servants, soldiers, doctors, and teachers, was championed by outgoing President Petro Poroshenko who needs to sign it into law before it takes effect, something he is expected to do.
Language became a much more sensitive issue in Ukraine, where many people speak both Ukrainian and Russian fluently, after Russia annexed Crimea and backed a pro-Russian separatist uprising in eastern Ukraine in 2014.
Poroshenko, who is due to step down soon after actor Volodymyr Zelenskiy trounced him at the ballot box on Sunday, put promotion of the Ukrainian language at the heart of his unsuccessful re-election campaign.
But Zelenskiy, who himself speaks Russian more frequently than Ukrainian, has said he wants to unite rather than divide the country and has said he has questions about the new law.
The new legislation requires TV and film distribution firms to ensure 90 percent of their content is in Ukrainian and for the proportion of Ukrainian-language printed media and books to be at least 50 percent.
Computer software must also have a Ukrainian-language interface although the law also allows the use of English or any other official language of the European Union.
Lawmakers cheered and rose to a standing ovation after the law was passed and sang the national anthem. Hundreds of people waving Ukrainian flags had gathered outside parliament to support the law.
"This is a historic moment, which Ukrainians have been waiting for centuries, because for centuries Ukrainians have tried to achieve the right to their own language," one of the authors of the bill, Mykola Knyazhytsky, said before the vote.
The make-up of the parliament has not changed since Zelenskiy's election win and remains dominated by a coalition supportive of Poroshenko.
Poroshenko had originally thought the language law would be approved before the election and would help boost his support, particularly in western regions where the Ukrainian language is predominantly used.
Its approval is potentially awkward for incoming president Zelenskiy, a comedian with no political experience.
Zelenskiy's stance on the new law is unclear. He said during the campaign he'd do everything to protect and develop the Ukrainian language, but also that he had questions about the new legislation.
In 2012, clashes between riot police and protesters erupted in Kiev after Ukraine's parliament approved a law that made Russian an official language.
Ukraine also has Romanian, Polish and Hungarian minorities that speak these languages. Last year, its relations with neighbouring Hungary soured after parliament passed a law that banned teaching in minority languages beyond primary school level.
A survey conducted by the Kiev International Institute of Sociology showed that the Ukrainian language is used by 32.4 percent of Ukrainian families, while Russian is used by 15.8 percent. About a quarter of Ukrainians use both languages.