* Ruling party rushes first reading vote through
* Angry opposition demonstrators march to soccer fan zone
* Clashes with police heighten tension on eve of Euro 2012 (Adds quotes, details)
By Richard Balmforth and Pavel Polityuk
KIEV, June 5 (Reuters) - A crowd of Ukrainians clashed with police in the capital Kiev on Tuesday after the ruling party rushed a contentious draft law upgrading the official role of the Russian language in the country through its first reading.
Several hundred opponents of the bill marched down the hill from parliament to be met by a cordon of police in riot gear as they tried to enter Independence Square, which is being transformed into a giant pedestrian 'fan zone' for the Euro 2012 soccer tournament starting this week.
They trampled official UEFA boards underfoot and a group of men scrambled up a structure supporting a giant display screen, on which spectators will view the soccer matches, and unfurled the Ukrainian flag.
Ranks of black-helmeted riot police pushed the crowd back after scuffles.
"Since they were not allowed to set up a tent protest near the parliament, the majority of protesters decided to occupy the fan zone on Maidan Nezalezhnosti (Independence Square)," said Ruslan Sekela, an activist for a nationalist pressure group, Nastup.
The Russian language issue is an emotive subject in the former Soviet republic of 45 million whose state language is Ukrainian but where a significant number of people speak Russian as their mother tongue.
Ukraine is hosting the month-long Euro 2012 tournament jointly with Poland. It opens with the first matches in Poland on June 8 and will end with the final in Kiev.
Supporters of the bill say a law is required to meet the needs of the large Russian-speaking population and allow their children to receive their basic schooling in their mother tongue.
Opponents regard the use of Ukrainian as a touchstone of sovereignty and say the encroachment of Russian will keep Ukraine in Russia's sphere of influence.
They say the Regions Party of President Viktor Yanukovich is trying to push the bill through so as to win back disenchanted votes in their Russian-speaking power bases in time for a parliamentary election in October.
Police threw up barriers round parliament on Tuesday as the vote took place while 6,000 demonstrators, more or less equally split between those for and against the draft law, massed in nearby streets.
Regions Party deputies pushed the first-reading vote through without any debate after forming a protective cordon around the speaker to pre-empt any interference by the opposition.
Last month, deputies of the opposition Batkivshchyna party of jailed ex-prime minister Yulia Tymoshenko prevented the issue going to a vote by blocking the podium, leading to a brawl.
Tymoshenko says Euro 2012 will cement Ukraine's rightful place in Europe and her supporters are not expected to try to disrupt the tournament to further her cause.
But Kharkiv, the eastern city where she is serving her sentence, is one of the four cities where Euro matches will be played in Ukraine and her supporters seem certain to try to take advantage of the presence of foreign media.
The bill would accord Russian the status of a "regional" language in predominantly Russian-speaking parts, and will be welcomed in Moscow where authorities complain that the language rights of Russian speakers in Ukraine are being violated.
Opponents say the move chips away at sovereignty and would mean that in traditional Russian-speaking areas Ukrainian would have no chance of becoming entrenched as a state language.
The bill will have a second reading later in the year and would become law when signed by Yanukovich. Opponents who turned out on Tuesday include world heavyweight boxing champion Vitali Klitschko who heads the Udar opposition party.
One of the protesters who scaled the supports of the giant screen on Independence Square, local historian Olexander Ushinsky, was detained by police.
"The werewolves of the (ruling) Regions Party decided to adapt a law which contradicts everything Ukrainian," he told reporters before being taken off by police. (Writing By Richard Balmforth; Editing by Robert Woodward)