PARIS, July 17 (Reuters) - France's parliament adopted a law on Thursday calling for more use of probation and other measures to reduce overcrowding in a creaking prison system which Justice Minister Christiane Taubira says does little to cut reoffending.
The move angered right-wingers who said the reform was proof that President Francois Hollande's Socialist government was soft on crime. Taubira antagonised many conservatives when she ushered in gay marriage last year.
Far-right leader Marine Le Pen, whose National Front party beat the ruling Socialists in European elections in May, has called the prison reform proof of the government's "laxity".
The population of France's ageing, rundown prisons has grown by a third in the past decade to nearly 70,000, largely because of tough sentencing laws introduced under former president Nicolas Sarkozy.
A key measure of the new legislation allows judges to choose probation over prison for criminals sentenced to less than five years' jail for crimes ranging from theft to assault.
It also does away with minimum prison sentences for repeat offenders and those convicted of violent crimes.
The centre-right UMP opposition said it would appeal to a constitutional court to have those Sarkozy-era measures reintroduced.
"The (new) law's effect will be to control prison populations by opening wide the doors that lead out and locking shut the doors that lead in," UMP deputy Georges Fenech said.
The law was passed after a final vote in the Senate, with Socialists and their left-wing allies voting in favour and centrist and right-wing parties voting against.
Supporters of the reform - including magistrates, defence lawyers, prison guards and human rights groups - say probation requires more active effort from offenders, rendering it more effective than prison. (Reporting by Emile Picy; Writing by Nicholas Vinocur; Editing by Andrew Roche)