One of America’s most prominent anti-gay campaigners has conceded that the battle against gay marriage is being lost.

Jim Daly, the chief executive of Focus on the Family, told an evangelical magazine that the majority of those under 30 now support gay marriage.

Focus on the Family backs anti-gay marriage campaigns and lobbies politicians to support “traditional marriage”.

Daly told World magazine: “We’re losing on that one, especially among the 20- and 30-somethings: 65 to 70 percent of them favour same-sex marriage.

“I don’t know if that’s going to change with a little more age – demographers would say probably not. We’ve probably lost that. I don’t want to be extremist here, but I think we need to start calculating where we are in the culture.”

A number of recent major polls have suggested that most Americans now back same-sex marriage. Daly said he had discussed the issue with gay marriage campaigners.

He explained: “I sat down with one. He said, ‘You guys haven’t done so well with marriage. Why are you upset about us having a try?’ We’ve got to look at our own house, make sure that our marriages are healthy, that we’re being a good witness to the world. Then we can continue to work on defending marriage as best as we can. ”

Daly theorised that God was boosting the popularity of gay marriage and polygamy to spur Christians into action and encourage them to end ‘easy’ divorces.

He said: “We’ve got to look at what God is doing in all of this. . . . Have we done such a poor job with marriage, is He so upset with our mishandling of it in the Christian community, along with our lust of the flesh as a nation, that He is handing us over to this polygamy and same-sex situation in order to, perhaps, drive the Christian community, the remnant, into saying, ‘OK, there’s no no-fault divorce in our church’?”

In another surprising announcement, Daly criticised Republican candidates on their third marriages and praised President Obama for raising his children with his first wife.

Without naming names, he said: “Some of the conservative candidates that we put up – between a couple of them recently, I think they had seven or eight marriages. That seems a bit hypocritical.”

Responding to Daly’s comments, Freedom to Marry president Evan Wolfson told Advocate.com: “Focus on the Family finally got something right – the American people are rejecting their anti-gay toxic rhetoric and punitive politics, and are siding with loving and committed couples seeking the freedom to marry.”