Thousands have taken to the streets of Istanbul and other cities in Turkey to protest against a bill that would allow child rapists to walk free if they marry their victims. The country's government insists the law would help resolve legal challenges caused by widespread child marriage in the country, yet critics argue the bill legitimises rape. If the law passes, men who sexually abuse girls under 18 without "force, threat or any restriction on consent" and marry them could have their convictions quashed or avoid prosecution. The UN children's fund said it was "deeply concerned" about the draft bill. "These abject forms of violence against children are crimes which should be punished as such, and in all cases the best interest of the child should prevail," said spokesman Christophe Boulierac. MPs approved the draft law in its initial reading. It will be voted on again on Tuesday. The bill comes after Turkey's constitutional court in July annulled part of the criminal code which classified all sexual acts with children under 15 as sexual abuse, a change that also prompted uproar. Turkish bar association Izmir Barosu said in a statement: "This proposal is clearly an attack on protecting children from sexual abuse. "We must make clear that any regulation against the protection of sexual abuse of children has no place in the public conscience. "The proposed regulation is intended to institutionalise child abuse. Physical and sexual violence against children and women is a crime."