Gay couples in all US states could be marrying sooner than expected, with a ruling likely to allow equal marriage in the entire country.

The Supreme Court has indicated that justices are likely to rule that no state can restrict marriage to only heterosexual couples under the Constitution.

Only two out of the nine justices – conservatives Clarence Thomas and Antonin Scalia – have dissented from the court’s refusal to block gay weddings from starting in Alabama.

Thomas admitted the court’s move “may well be seen as a signal of the court’s intended resolution” as it considers cases from Kentucky, Michigan, Ohio and Tennessee. So even those opposing the ruling expect the decision to be ruled in favour of LGBT couples.

Oral arguments in the cases are due in April, with a decision expected by the end of June.

Sarah Warbelow, the HRC legal director, has said “there is virtually zero risk that [the justices] will issue an anti-equality ruling this summer.”

37 out of the 50 US states have already legalised marriage for same-sex couples.