Following the Obama administration’s announcement that it will no longer defend the Defence of Marriage Act, US conservatives say they will make gay marriage an election issue.

According to the Washington Post, conservatives said they expect that a Republican challenger to President Obama will highlight the issue next year, even putting it on an equal footing with the economy.

Well-funded anti-gay groups such as the Family Research Council and the National Organisation for Marriage said Republicans would have to tackle the issue head-on to avoid alienating traditional supporters.

Tony Perkins, of the Family Research Council, told the newspaper: “It is incumbent upon the Republican leadership to respond by intervening to defend DOMA, or they will become complicit in the president’s neglect of duty.”

But Jon Davidson, legal director of the gay-rights group Lambda Legal, said he doubted how much impact the issue would have.

“I think they will try to turn this into a major election issue,” he said. “But the people who feel strongly that same-sex couples should not be allowed to marry were not going to vote for President Obama anyway.”

This week, the administration said it would not longer defend the law, known as DOMA. A Democratic senator is to introduce a bill next week to repeal the law.

DOMA restricts federal recognition of marriage to heterosexual couples – meaning that even states which want to give gay couples full equality cannot do so. It also means that married gay couples cannot file joint tax returns or receive survivors’ social security benefits.

It is not clear what effect the announcement will have on current state-level gay marriage wrangles. Gay marriage opponents are apt to claim it will strengthen their case, while supporters say it will give the ‘pro’ side a boost.

Although the President does not support gay marriage, his spokesman said this week that he is “grappling” with his views on the issue and has always opposed DOMA.

Six states currently allow gay couples to wed. Others allow forms of civil union or recognition of gay marriages performed in other states. Thirty have constitutional bans on the practice.