After the American Civil Liberties Union filed a lawsuit to push for equal marriage last year, Pennsylvania is expecting a ruling on legalising same-sex marriage today.

The ACLU filed the lawsuit in July 2013 on behalf of 21 gay and lesbian couples. The federal lawsuit alleges the state’s Defense of Marriage Act including refusal to marry same-sex couples violates the fundamental right to marry and the Equal Protection Clause of the Fourteenth Amendment, according to the ACLU.

Same-sex couples recently filed for a summary judgement in the same-sex marriage ban case, almost a year after the original lawsuit by the ACLU.

The Union announced on Twitter that a Pennsylvanian judge is expected to make a decision on lifting the ban stopping same-sex marriage on 20 May 2014.

During the original lawsuit process, Witold Walczak, legal director of the Pennsylvania ACLU said: “What we’re looking for is for the court to say: Here we are in the 21st century, and you cannot prohibit somebody from participating in this wonderful institution we call marriage.”

Pennsylvania’s State Treasurer announced in March that he’s backing a couple who are legally challenging the state’s ban on same-sex marriage.

The decision will be posted on the court’s website after the ruling is made public.

Yesterday, Oregon became the 18th state to legalise equal marriage with the same-sex marriage ban being struck down by Judge Micheal McShane.