(Repeats story published late on Wednesday) By Jan Lopatka
PRAGUE, March 18 (Reuters) - The leftist opposition in the Czech Republic has its best chance ever to topple the centre-right cabinet, a step that could undermine Prague's current presidency of the EU as the bloc fights economic crisis.
An ouster next Tuesday would also threaten Czech ratification of the EU's Lisbon treaty and cast more doubt on an already sidelined plan to build a U.S. missile defence radar system in the country.
"When compared with previous no-confidence motions, this time the chances of the cabinet falling are the greatest," said Pavel Saradin, a lecturer at Palacky University.
The minority administration's fall would not lead straight to an early election, and Prime Minister Mirek Topolanek's team led by the right-wing Civic Democrats could stay on, possibly for months, while parties hammer out what to do next.
But the government's fall would weaken policymaking as the Czechs try to steer the EU's efforts to battle economic crisis.
"Topolanek is the EU chief now and if his government lost confidence, it would weaken him significantly," said Saradin.
The Czech opposition has accused the government of economic mismanagement, but the trigger for the vote was an allegation that Topolanek's aide had tried to persuade a TV station to scrap a report damaging to an independent parliamentary deputy sympathetic to the government.
EROSION OF SUPPORT
The three-party cabinet was formed in 2007 with the support of 100 votes in the 200-seat lower house, and won an initial confidence vote thanks to backing from two opposition renegades.
Over time, both government and opposition parties have lost more deputies. The government now has 96, and the opposition 97. The rest are defectors who vote independently.
So far there have been enough votes for the government to scrape by. But some independents' support is waning.
"It does not make sense to keep holding this up," former Civic Democrat deputy Juraj Raninec told Reuters. He said he may vote against the government if there is a solid alternative.
The Social Democrats may want an election sooner rather than later, as their lead in opinion polls has been shrinking.
But calling an early vote is not easy. If the cabinet fell President Vaclav Klaus, a rightist estranged from the Civic Democrats, would pick a new prime minister, which may take time.
"The president could even leave the government, without confidence, in power until the end of its term, which is absurd," said Vladimira Dvorakova of the Prague School of Economics. "For Europe it's a slap in the face. Being run by a government without confidence would degrade the whole concept."
An early election can be held if three attempts to form a cabinet fail, or if parties agree to change the constitution. The main government and opposition parties may also agree on a government, perhaps including non-partisan experts.
The government's fall could threaten approval of the Lisbon treaty, the EU's pact on institutional reforms that has been adopted by all EU states except for the Czechs and Ireland. Topolanek grudgingly supports the treaty but many of his party colleagues do not. If the Civic Democrats lose government responsibility, there will be less pressure on them to approve the document in the upper house, the Senate. (Additional reporting by Jana Mlcochova; editing by Andrew Roche)