A ruling by Malaysia’s highest court in a high-profile marital dispute could help determine whether Islamic courts have the power to decide the fate of non-Muslims, a deeply divisive issue in this mainly Muslim nation.

The Federal Court is expected to rule Thursday in the case of Subashini Rajasingam, a 29-year-old ethnic Indian Hindu who is trying to prevent her Muslim convert husband from seeking a divorce in a Shariah court and to stop him from converting their younger son to Islam. Subashini is not contesting the divorce, but wants it to be decided in a civil court.