Japan's top court has decided to hold a deliberation on whether a legal provision requiring people to undergo sex change surgery to switch their gender registry is constitutional.

The Supreme Court three years ago ruled that the provision does not violate the Constitution.

This time, the Supreme Court will examine the case at its 15-member Grand Bench. Observers say the move indicates a new judgment may come from the court.

The petition is being filed by a person who was born as a man and yet leads a life as a woman. The person is demanding legal recognition as a woman without surgery.

The provision in the law for people with gender identity disorder requires absence of genital glands to legally change sex.

The petitioner says the provision that effectively forces surgery is a grave human rights violation and unconstitutional.

In the 2019 case, the top court said a possible birth of a child with retained reproduction ability could bring confusion to society.

The court ruled the provision does not violate the Constitution when comprehensively examined in view of its purpose.

The petitioner's lawyer Minami Kazuyuki said he is surprised that the Supreme Court has decided to take the case at the Grand Bench two years after he filed it. He added that he expects the judicial authorities to examine the case carefully.