A Dáil vote is due to take place on Tuesday, following today's debate of an Opposition bill criminalising those who buy sex from women and girls.
Independent TD Thomas Pringle said there was nothing voluntary for the many women forced into prostitution.
He said the law needed to be updated to account for trafficking.
Government chief whip Paul Kehoe apologised on behalf of Minister for Justice Alan Shatter that he was not in the Dáil for the debate but said he had a commitment elsewhere.
Mr Kehoe said it was important to review the the wide body of criminal law to make sure it was up to date with the criminal environment in which it operated.
He said the minister was acutely conscious that many women involved in prostitution had limited life choices.