The Welsh secretary has sought to clarify his views on gay marriage after claiming same-sex couples could not provide a “warm and safe environment” in which to raise children.
On ITV Wales’ Face to Face programme, David Jones said this was why he had voted against the government’s legislation for same-sex marriage.
He has insisted he is not opposed to gay couples raising children.
But the Labour Party has demanded a public apology.
The Conservative MP has said he is not homophobic and has “people in my life who are important to me who are gay”.
“I did not say in the interview that same-sex partners should not adopt children and that is not my view,” said the MP, who had been explaining his decision to vote against the legalisation of gay marriage.
“I simply sought to point out that, since same-sex partners could not biologically procreate children, the institution of marriage was one that, in my opinion, should be reserved to opposite sex partners.”
“I made the point of stressing that I was fully supportive of committed same-sex relationships. I also strongly approve of civil partnerships,” Mr Jones added in a statement.
In the original interview with ITV Wales, Mr Jones said the institution of marriage was meant to provide “a warm and safe environment for the upbringing of children, which is clearly something that two same-sex partners can’t do.
“Which is not to say that I’m in any sense opposed to stable and committed same-sex partnerships,” he said.
But shadow Welsh secretary Owen Smith has written to David Cameron dismissing Mr Jones’ explanation as “obfuscation” and is calling on the prime minister to demand his cabinet colleague withdraw the remark and apologise.
Mr Smith wrote that the remarks “betray a lack of acceptance for same-sex relationships that is out of step with the majority of people in our country.
“I believe you should now ask him to withdraw the comments and apologise. I would also like to ask whether you find it acceptable or appropriate for the most senior Conservative MP in Wales to make these comments?” he added.
“David Jones has chosen not to apologise for these unacceptable comments,” Mr Smith said.
“It is time for David Cameron to make clear whether he thinks it is unacceptable for the Welsh secretary to make these comments.”
A spokesman for Mr Cameron said on Friday night: “Gay marriage and gay adoption are both conscience issues and, as such, have been treated as free votes. The prime minister is a supporter of both.”