Lawmakers argued the law, which previously required prosecutors to show that an attack involved "violence", had failed to protect people attacked while unconscious or coerced into having sex

(Corrects parliament's decision in 1st paragraph to clarify that law is yet to be approved and adds details about final vote on law amendment in 4th and 5th paragraphs. Changes headline.)

LISBON, Jan 11 (Reuters) - Portugal's parliament unanimously agreed on Friday to further discuss a law amendment to expand the definition of rape to cover all sex without consent, hoping to join just seven EU countries with such a wide definition.

Lawmakers and campaigners in Portugal argued the law, which previously required prosecutors to show that an attack involved "violence", had failed to protect people attacked while they were unconscious or coerced into having sex against their will.

The amendment aims to bring Portuguese legislation closer to the Istanbul Convention, an international treaty on preventing and combating violence against women.

Lawmakers unanimously voted to submit the amendment to a constitutional committee, where it is now undergoing changes, but they haven't formally voted on the law itself.

Members of parliament have 60 days to discuss the amendment and the final vote is expected as soon as the conversations are over. But because of the unanimous vote on the amendment it is highly likely to be approved.

The Istanbul Convention was ratified by the Portuguese government in 2012 and has been in force since 2014 but critics have argued authorities failed to fully incorporate it into law.

In September last year, a court in Porto ruled that two men who had sex with an unconscious 26-year-old woman were not guilty of rape because the incident was a "mutual seduction".

Neighbouring Spain saw protests last year over the case of a woman who was attacked by five men at the Pamplona bull running festival in 2016. The men, who filmed themselves cornering her in alley and having sex with her, were accused of gang rape but found guilty only of the lesser offense of sexual abuse, after judges ruled prosecutors could not prove the attack was violent.

"Crimes of sexual nature and rape (in Portugal) are based on the existence or non-existence of violence and we want it to be based on the existence or not of consent," Andre Silva, one of the lawmakers who proposed the amendment, told Portuguese radio station TSF.

Article 36 of the Istanbul Convention states that authorities shall take all necessary measures to ensure that engaging in non-consensual sex is always treated as a crime.

Portugal has followed in the footsteps of Belgium, Cyprus, Britain, Germany, Iceland, Ireland and Luxembourg which have all passed consent-based rape legislation.

According to Amnesty International, one EU woman in 10 experiences some form of sexual violence after the age of 15.

"Rape laws in place will not resolve everything but it is an important step towards changing attitudes and achieving justice, by making it clear that sex without consent is rape and it cannot continue with impunity," Amnesty said on its website.

(Reporting by Catarina Demony Editing by Axel Bugge and Peter Graff)

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