LISBON, Portugal (AP) — Portugal’s parliament voted for the third time in almost two years Friday in favor of allowing euthanasia, though as happened in the previous attempts the country’s Constitutional Court or president could stop the bill becoming law.

Lawmakers passed a bill permitting euthanasia and physician-assisted suicide in Portugal, the Speaker of Parliament said, though exact voting figures were not immediately available.

Left-of-center parties in the mostly Catholic country were the driving force behind the bill, as they were with laws allowing abortion in 2007 and same-sex marriage in 2010.

The bill requires the head of state’s approval to become law. President Marcelo Rebelo de Sousa could choose to block the legislation again or send it once more to the Constitutional Court for vetting. That could hold up the law for several months.

Imprecise wording and unconstitutional aspects frustrated the two previous attempts to get the law enacted.

Euthanasia is when a doctor directly administers fatal drugs to a patient. Medically assisted suicide is when patients administer the lethal drug themselves, under medical supervision.

New rules in the latest version of the bill include the mandatory involvement of a psychologist in the process from beginning to end and a minimum wait of two months between the request and death.

The bill states that the patient’s request must be “repeated, serious, made freely and informed, in a situation of very intense suffering, with a definitive injury of extreme seriousness or a serious and terminal illness.” The patient requesting death must express the wish freely at least six times.

The request is approved or rejected, and the entire procedure is overseen, by a national committee made up of two legal experts, a doctor, a nurse and a specialist in bioethics.