* Romanian PM in Brussels to defend legal practices
* Corruption, rule of law in Romania facing EU scrutiny
* Government pursues impeachment of president (Adds comments from Romanian PM and president, changes dateline)
By Radu Marinas and Justyna Pawlak
BUCHAREST/BRUSSELS, July 11 (Reuters) - Romania's prime minister assured European leaders on Wednesday that his government was fully committed to democracy and the rule of law after drawing fire for suspending President Traian Basescu by a vote in parliament.
In the latest clash between the poor Balkan state's two dominant political forces, premier Victor Ponta's leftist Social Liberal Union (USL) wants to remove the conservative Basescu for good by a referendum the government has called for July 29.
Ponta's government has accompanied the impeachment bid with a string of emergency decrees that have broadened its power but raised concerns that it may be skirting constitutional checks and balances and backsliding on obligations to democracy.
Following rebukes from the European Union, EU paymaster Germany and the United States, Ponta must convince fellow EU leaders he is respecting common principles or jeopardise an IMF aid deal designed to buttress an economy now in recession.
The dispute could mean a negative assessment on July 18 from EU officials who are monitoring Bucharest's judicial system and anti-corruption efforts. Previous such EU reports have been cited before as grounds for keeping it and its Balkan neighbour Bulgaria out of the bloc's passport-free travel area.
Both were allowed five years ago to join the union, but EU partners have remained wary of their democratic credentials and a culture of graft, two decades after communist rule ended.
Ponta travelled to Brussels on Wednesday for meetings on Thursday with European Commission President Jose Manuel Barroso and European Council President Herman Van Rompuy.
"I will restate my unswerving commitment to democracy and the rule of law," Ponta, a 39-year-old lawyer, said in a statement ahead of the visit.
Following meetings at the European Parliament in Brussels, Ponta said his government's actions were in line with EU rules, but it would take any criticism to heart.
"We are ready not only to accept conclusions but also to act immediately if something is not considered to be (in line with) EU standards," he told reporters.
But he also shot back at critics, saying linking judicial system reforms in Romania with its chances of joining the Schengen travel zone was not fair. "I hope this is not going to happen," he said.
At issue is how Ponta's government has pursued the impeachment of Basescu, including making an abortive attempt to dismiss constitutional judges and replacing the national ombudsman with one of its own party loyalists - a move that effectively removed any means of countering emergency decrees.
The USL changed the rules on recall referendums, so that a simple majority of ballots cast, rather than of registered voters, would suffice to oust Basescu, a folksy former sea captain.
The constitutional court upheld the first part of that law on Tuesday but introduced a minimum 50-percent turnout threshold to validate a referendum - giving Basescu a fighting chance to survive, even if his supporters stay away from the ballot. Voter turnout in recent elections has been well below that level.
Ponta has called for an extraordinary session of parliament to bring the referendum laws into line with the court ruling.
That brought a cautious welcome from U.S. ambassador Mark Gitenstein, who warned that failure to do so would "knowingly provoke a very dangerous constitutional crisis".
The dispute is the latest clash between Basescu and his centre-right allies versus the Socialists, reformed heirs of the Communist party once run by one of the Soviet bloc's most unyielding dictators, Nicolae Ceausescu.
Ponta's camp insists Basescu has abused the constitutional powers of what they say is a mostly ceremonial post as head of state to favour his political allies.
Politicians close to Basescu say his adversaries are retaliating for the corruption conviction this year of former prime minister Adrian Nastase, a senior member of Ponta's USL.
"These guys are sacrificing the country's stability for the sake of total power," Basescu himself said on Wednesday during the launch of his referendum campaign.
Last week, Basescu's interim replacement as president - Crin Antonescu - appeared to suggest that a pardon for Nastase could not be ruled out if Basescu were removed and replaced. Basescu loyalists seized on that comment to argue that the USL was gunning for the president for purely partisan reasons.
Analysts say Ponta might rethink his drive to oust Basescu now the judges have ruled the referendum must reach a minimum turnout - and given the possibility that the constitutional court could also withhold its validation of any result.
In 2007, Basescu survived a similar impeachment referendum launched by the Socialists. But since then, he has faced wider public criticism, accused of failing to do his share to root out corruption. Years of painful austerity measures by previous right-of-centre governments have also taken their toll, driving Basescu's personal approval rating down to about 10 percent.
The USL did well at local elections held last month and is expected to be re-elected in a parliamentary vote in the autumn.
But Ponta is also under pressure. He has faced calls to resign since being accused of plagiarising his doctoral thesis, while the saga of Nastase's conviction was back in headlines that embarrassed the USL last month, when the former premier tried to kill himself before starting his jail sentence. (Additional reporting by Ioana Patran in Bucharest and Ethan Bilby in Brussels; Editing by Michael Winfrey and Alastair Macdonald)