Despite changes across the US in support of same-sex marriage, a study has shown that Republican voters continue to oppose it.

The poll, released by two groups showed that 74% of Republicans and those who lean towards Republican views support the idea that marriage is between one man and one woman.

The poll was commissioned by anti-gay conservative groups American Values and the Family Research Council.

It was conducted in March across 801 Republican and Republican-leaning voters.

Other polls have shown that younger Republican voters are more likely to support same-sex marriage. A Pew Research Center study in march found that 61% of 18-29-year-old Republicans supported same-sex marriage, but only 22% of those aged 65 and over did.

Gary Bauer, the president of American Values told Politico: “This survey should remind political and cultural leaders that this debate is far from over… Public policymakers are doing a great disservice to themselves and future generations by continuing to misread the convictions of the American people.”

This poll comes in contrary to recent efforts to make the GOP more inclusive, but some have noted that the core-supporters of the party may still be opposed to same-sex marriage.

The president of the adamantly anti-gay Family Research Council Tony Perkins said the “vast majority of the GOP base continues to believe that marriage is a non-negotiable plant of the national platform and want to see their elected officials uphold natural marriage as the national standard.”