The idea is to get away from punishment towards treatment

Carlos Borges

Previously, drug users and those caught in possession of small amounts of banned drugs for personal use faced up to a year's imprisonment.

The sale and trafficking of illegal drugs remain crimes.

Under the new law police will report drug takers to special local authority commissions which will ensure addicts seek treatment.

Heroin users are patients, not criminals

"The idea is to get away from punishment towards treatment," government spokesman Carlos Borges told Reuters news agency.

The ruling Socialist Party, which is one seat short of an outright parliamentary majority, was backed in the vote by the Communist Party and other left-of-centre parties.

Referendum call

The main conservative opposition party, the Social Democrats, had urged the government to call a referendum on the proposed new law.

Prime Minister Antonio Guterres rejected the referendum idea on the grounds that the change being put forward was not sufficiently sweeping to merit a national vote.

A significant proportion of prisoners in Portugal's jails are there for drug-related offences, but the number of people sentenced simply for possession or consumption is very low.

"It would not be more than a couple of dozen," said one government official.

Portugal becomes the third member of the European Union, after Spain and Italy, to decriminalise the consumption and possession of small quantities of drugs.