Senator David Norris has said that prostitution being illegal is putting sex workers in danger.
Senator Norris said that prostitution is still happening, but its illegal status is driving people "underground", putting workers in danger.
It comes after Amnesty International voted earlier this week to create a plan to protect sex workers, rather than punish them.
The human rights organisation voted in support of the full decriminalization of all aspects of sex work at a meeting in Dublin earlier this week.
Senator Norris said people have been making themselves available for sexual gratification in return for money since time began.
"We drive it undergorund, where it is extremely dangerouus for the sex workers involved," he said. "All these do-gooders: do they actually think that prosutituion will end? Of course it won't."
The Sex Workers Alliance of Ireland representatives this week expressed similar concerns, with spokesperson Kate McGrew saying sex workers who are victims of crime fear to report it.