A federal judge was urged on Wednesday to strike down the state of Oregon’s same-sex marriage ban by the state itself, as well as the plaintiffs in a lawsuit brought against it.

As there were no arguments in favour of the same-sex marriage ban in the state, lawyers on both sides of the lawsuit urged Judge Michael McShane to strike down the ban.

Lawyers for the plaintiffs, four gay and lesbian couples, and lawyers for the state of Oregon both pushed McShane towards the same outcome at Wednesday’s hearing.

In February, the state’s Attorney General, Ellen Rosenblum declined to defend the ban, arguing that it would not stand up to a constitutional challenge.

Judge McShane who is also overseeing a parallel case, did not indicate which way he was leaning. He asked both sets of lawyers to back up their arguments for why the ban should be struck down.

As well as same-sex marriages being able to take place in the state, advocates also want out-of-state same-sex marriages to be recognised.

Two arguments were made against the ban, known as Measure 36 – that it is unconstitutional as it serves no legitimate government interest – and that marriage is a fundamental right for all Americans.

The National Organisation for Marriage has since sought permission to defend the ban in court, after the state declined to defend the law.

A 2004 constitutional amendment approved by 57% of voters to 43%, defined marriage as exclusively between one man and one woman.

Same-sex marriage advocates also say they have collected enough signatures to force a ballot measure on the issue, but that they will discard it if a judge strikes down the ban before the 23 May due date to hand over the petition.