The drivers, opposing government plans to do away with taxi permits as part of a drive to free up various occupations, blocked several major roads and bridges around the Polish capital in the morning and ended their protest hours later in front of the parliament building.

Similar protests took place in other Polish cities, including Wroclaw and Gdansk, which will also host Euro 2012 matches starting on June 8.

"We don't rule out the possibility of doing something on June 8," said Pawel Biedrzycki, one of the protest organisers in Warsaw. "But we are also soccer fans, so we really don't want to block (the city). It would be our last resort."

Several Polish labour unions have already said they may use the spotlight of the Euro 2012 tournament to publicise their differences with the government over an unpopular law to raise the retirement age.

The protests threaten to spoil Prime Minister Donald Tusk's hopes that co-hosting one of the world's biggest sporting events with Ukraine will help boost the government's lagging public support.

The tournament has already been marred by threats by numerous European leaders to boycott matches in Ukraine over the jailing of opposition leader Yulia Tymoshenko.

(Reporting by Chris Borowski and Jaroslaw Kowalski; Editing by Jon Hemming)

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