In an unexpected move, the Massachusetts Supreme Judicial Court announced that it would hear oral argument in a case seeking to stay the court’s decision, which legalized same-sex marriage a year ago.

As a result of that decision, same-sex couples have been permitted to marry in Massachusetts since May 17, 2004.

The Thomas More Law Center filed the appeal on behalf of C. Joseph Doyle, executive director of the Catholic Action League of Massachusetts.

The appeal asks the Court to stay its decision so that the process currently under way to amend the state’s constitution and define marriage as the union of one man and one woman can proceed unhindered.

The Law Center had initially petitioned a single justice of the court April 20, pending the constitutional process currently under way.

The petition and an ensuing request for an expedited appeal were denied. But the full Court ultimately decided that Doyle’s appeal could “proceed in the ordinary course,” keeping the case alive.

As a result, Doyle filed an appeal and the Massachusetts Supreme Court just announced that it has agreed to hear it. This is the last legal action capable of stopping this decision.

“The fact that the Massachusetts Supreme Court has decided to take up this issue again is remarkable,” said Richard Thompson, president and chief counsel for the Law Center. “Clearly, the tide is changing in America — moral values do matter.”

Citizens for the Preservation of Constitutional Rights has joined the Law Center in arguing the case.