Hundreds of people have been jailed under the current law, introduced by President Hamid Karzai.'Lack of assurance'
The decision to seek parliamentary approval for the law had split women activists.
Some had said opening it up for debate in parliament could pave the way for conservatives to amend it and weaken protection for women - or even throw it out altogether.
One of those against the move was prominent MP Farkhunda Zahra Naderi. She told the BBC after Saturday's events in parliament that her fears had been proved right.