Three-quarters of Republican Members of Congress have neglected to sign a court brief opposing same-sex marriage, ahead of a Supreme Court battle.

The Supreme Court is set to hear opening arguments on April 28 in a case that could end up bringing same-sex marriage to all 50 states.

Ahead of the case, the court has received over a hundred briefs from interested groups – but a brief from the GOP opposing the measure failed to attract support from a majority of the party’s lawmakers.

In a sure-fire sign that some Republicans don’t want to be seen on the wrong side of history in the case, just 57 out of the party’s 299 Members of Congress signed the brief, which argues states should be allowed to decide if gays are allowed to marry.

Just six Senators and 51 members of the House of Representatives signed the brief – and it wasn’t signed by Republican House Speaker John Boehner.

Meanwhile, a brief from the Democrats in favour of equality was signed by 211 of the party’s 232 Members of Congress – with 167 House members and all 44 of the party’s Senators signing.

Just 21 Democrats neglected to sign their party’s brief – compared to the 242 absent Republicans.

The Republican brief warns of allowing same-sex marriage: “Such a decision could damage the rights of a self-governing people.

“It would set an unwarranted precedent, with effects far beyond this case, of federal encroachment into a traditional area of state concern, and of judicial pre-emption of an area that the Constitution allots to democratic process.”