WARSAW, Poland — Poland’s lawmakers on Thursday opened a divisive debate on changing the restrictive anti-abortion law, among Europe’s toughest, in this predominantly Catholic nation.

The 10-month-old conservative government considers the current law to be too liberal. The policy of Prime Minister Beata Szydlo’s government focuses on various forms of support for large families in order to boost the country’s sagging birth rate.

The lower house discussed two opposing drafts proposed by civic groups. One, from Stop Abortion group and supported by the government, calls for a total ban on abortions. The other one, backed by the opposition, is seeking to allow abortions through the 12th week of pregnancy, like in many European Union nations. The lawmakers will decide Friday whether to send the drafts for fine-tuning in special commissions.

The house is dominated by the ruling Law and Justice party whose members declare attachment to the Catholic Church and to its insistence that human life has to be protected from conception until natural death. Observers say the government is bowing to the expectations of many Church leaders, whose support helped the party win elections last year.

Hundreds of activists from both sides of the abortion debate picketed in front of parliament. The anti-abortion group, some with small children in pushchairs, prayed aloud, while pro-abortion rights activists were clad in black to signify mourning over the restrictions in the availability of abortion.

Under 1993 legislation, abortion is currently allowed in Poland if the woman’s life or health is endangered, the pregnancy results from rape or incest or the fetus is irreparably damaged.

The law was criticized by both sides. Opponents of abortion said the law allows for termination of pregnancies when the fetus is diagnosed with Down syndrome. Those seeking liberalization said the law leads to about 100,000 illegal abortions each year.