Opponents complain that the new law concentrates too much power in the hands of the winning party and does not allow voters to directly choose their representatives.  Opposition parties have appealed to Sergio Mattarella, the Italian president, not to sign off on the bill in order to prevent it becoming law. They have also threatened to organise a popular referendum to try to have it repealed.  Renato Brunetta (left) and Silvio Berlusconi (Getty Images)  "We say no, because this law has been conceived to create a one-party state," said Renato Brunetta, floor leader of former prime minister Silvio Berlusconi's Forza Italia party. Forza Italia previously supported the bill, but changed its mind following a dispute over the election of Mattarella in January.  The 630-seat Chamber of Deputies approved the bill in a secret ballot by 334 votes to 61. With most opposition politicians refusing to take part, the result indicated that 40-50 dissidents in Mr Renzi's Democratic Party (PD) voted against him.  Analysts said the chief beneficiary of the reform was likely to be the 40-year-old Mr Renzi himself, who faces a weak and divided opposition and holds a clear lead in opinion polls.  Mr Renzi brushed aside resistance from PD rebels last week by imposing confidence votes to prevent further amendments being added, which would have prolonged its parliamentary passage.  Together with a separate reform of the senate that will see the upper house reduced to a non-elected chamber with limited powers, the overhaul is intended to ensure stable governments able to last a full five-year term.  Mr Renzi said Italy, one of the world's slowest growing economies, had had 63 governments since the Second World War but that none had been strong or durable enough to push through core reforms, despite wide recognition that change was needed.  Here are the main aspects of the new law:  The new electoral law, which only applies to the lower house of parliament, cannot be used until the reform of the senate is completed.
Matteo Renzi, the Italian prime minister, hopes the new legislation - based on   proportional representation - will be a point of reference for political   stability