Far-right protesters clashed with police in Budapest tonight after nationalist leader Gyorgy Budahazy, who has been wanted by the police since disturbances began last September, was arrested.
The protests by the parliamentary opposition and far-right groups marked a renewed campaign to oust Ferenc Gyurcsany, whose admission that he lied about the budget to win elections last year triggered seven weeks of violent demonstrations.
A rally by the main opposition Fidesz party attracted around 100,000 people, including radical groups.
After the main rally police used tear gas and water cannon against a few hundred people who threw stones. There were no immediate reports of injuries among police or protesters, but witnesses said the protesters had beaten some photographers.
At a midday ceremony marking the country's 1848 uprising against Habsburg rule, Budapest mayor Gabor Demszky had to be protected with umbrellas against eggs thrown from a whistling, booing crowd of far-right protesters.
Parliament is still barricaded from last year's protests in which 800 were injured. A heavy police presence kept the demonstrators far away.
Since winning elections last April, Gyurcsany's government has broken campaign promises by hiking taxes and cutting spending to rein in Hungary's budget deficit which, at 10 per cent of gross domestic product, is the biggest in the European Union.
He has won the approval of investors who have pushed the forint up 10 per cent against the euro in the past six months as he is seen to be making the first real attempt to break Hungary's five years of surging budget deficits.
But the 45-year-old real estate millionaire has deepened the political divide in Hungary and is accused by his opponents for creating a climate of fear.