By Alexei Kalmykov and Alessandra Prentice
KIEV (Reuters) - Ukraine's parliament approved on Thursday judicial reforms that Western backers say are needed to fight corruption, in the first constitutional vote the ruling coalition has pushed through since an overhaul of the government in April.
Bribery in the court system is seen as a major obstacle to Ukraine's broader reform effort under a $17.5 billion International Monetary Fund bailout program that political infighting has threatened to derail.
The bill, which aims to curb political influence on the appointment of judges and limit their immunity in case of malpractice, was backed by 335 lawmakers, 35 more than the required votes needed for changes to the constitution.
The result was welcomed by Ukraine's international backers, including the United States and the European Union, which along with the International Monetary Fund have urged Kiev to step up its fight against corruption.
The IMF, which is in negotiations with Ukraine for disbursing more aid worth $1.7 billion, has threatened to suspend such assistance if matters do not improve.
"We will return to Ukrainians the right to truth, the right to justice, fight for a fair trial in Ukraine," President Petro Poroshenko told parliament before the vote.
"In the last two weeks my desk has been littered with appeals from our partners, EU leaders, the United States and Canada, Australia and Japan, addressing me and you, members of parliament. Don't stop the pace of decisive reforms and implement judicial reform."
Senior EU officials Federica Mogherini and Johannes Hahn said they hoped the vote would pave the way for other changes to the constitution, including a law to give greater independence to regions that is required under the 'Minsk' peace deal with pro-Russian separatists.
"We hope today's vote will create momentum for the adoption in the final reading of the pending constitutional amendments related to decentralization and other important reforms," they said in a joint statement.
The judicial legislation was opposed by some lawmakers, including the servicewoman Nadiya Savchenko, who returned home last week after spending nearly two years in a Russian jail and is viewed by many Ukrainians as a national heroine.
In an emotional appeal she asked the parliament to keep its hands off the constitution, "or else the country will blow up like a hand grenade". She did not take part in the vote.
The reform is aimed at making judges more professional. It partly limits their immunity from prosecution, which used to be unconditional. From now on they will be appointed by a judicial council rather than parliament, which is intended to shield them from political meddling.
"Today we have a historic opportunity to carry out this judicial reform, to break the back of the current corrupt judicial system," the head of the opposition Radical Party Oleh Lyashko said.
(Additional reporting by Gabriela Baczynska, Editing by Matthias Williams and Richard Balmforth)