A Labour AM has been accused of "lowering the tone" of the EU debate by comparing a Leave vote to a man getting divorced because he thinks "young women are available".
Pro-EU Swansea East member Mike Hedges made the remark while explaining why he thought Brexit posed a risk.
UKIP Wales leader Nathan Gill, who is campaigning for a Leave vote, said the remark was "shameful".
Mr Hedges later apologised for the remark.
He had told BBC Wales: "It's like getting divorced after 43 years.
"It might look better on the outside with all these young women available to you.
"But I think the reality may well be something different."
In response Mr Gill said: 'It's shameful for anyone - let alone a member of the Welsh assembly - to lower the tone of debate in a way that may be seen as offensive.
"The vote on 23 June is a once-in-a-lifetime opportunity," he added.
"A vote to Remain is a vote to continue to send £350m to the EU every week, rather than spending it on our own priorities such as higher education and scientific research."
Mr Hedges later apologised on Twitter, saying the comments "should have been gender neutral".