Italy's lower house of parliament in a secret ballot on Monday voted a fiercely contested electoral reform bill into law with 334 votes in favour, 61 against and four abstentions.
In a snub to the government, opposition parties left the chamber before the vote. And rebel lawmakers from prime minister Matteo Renzi's ruling centre-left Democratic Party voted against the bill.
The chief whip for former primer Silvio Berlusconi's conservative Forza Italia party, Renato Brunetta called the vote "a dark day for democracy and parliamentary democracy".
One of the key and most contested elements of the new electoral law is a bonus of 15 percent of extra seats awarded to the party that obtains 40 percent of votes, giving it a working majority in parliament.
Renzi claims the winner's bonus will produce more stable governments. Its supporters also claim it will avoid the fragile coalition governments that have characterised Italian politics.
Another provision of the new election law that its critics argue is undemocratic is that the head of each party list is nominated by the party and automatically wins a seat in parliament if the party wins.
The new law will enter into force on 1 July 2016. It only applies to the lower house of parliament because a separate reform bill is being designed to make the upper house Senate a leaner body of regional government representatives with reduced powers.
