Poland's constitutional court will on Thursday look into a bid to tighten the devout Catholic country's abortion law, which is already one of Europe's most restrictive.
Lawmakers from the governing right-wing Law and Justice (PiS) party would like to ban the abortion of foetuses with congenital birth defects -- currently one of the few instances under which a pregnancy can be legally terminated in the EU member.
Many Polish women bridled when PiS backed a bill originating as a popular petition earlier this year, prompting conservative lawmakers to refer the matter to the constitutional court.
The tribunal, whose main role is to ensure that any laws comply with the constitution, underwent government reforms in 2016, leading critics to contend it is stacked with PiS allies.
A favourable ruling from the court could pave the way for lawmakers to approve the draft legislation. If so, PiS-allied President Andrzej Duda said he would sign it into law.
Since 1993, Poland has only allowed abortions if the pregnancy is a result of rape or incest, if it poses a threat to the mother's life or if the foetus is deformed.
The NGO Akcja Demokracja (Action Democracy) said more than 210,000 people had signed its petition against an even stricter abortion law.
Earlier this year, Council of Europe Commissioner for Human Rights Dunja Mijatovic called for the draft legislation to be rejected.
"With almost all pregnancy terminations lawfully carried out in Poland today falling under this category (congenital defects), the bill -– if adopted -– would result in virtually outlawing abortion and seriously affecting rights and safety of women," she said.
The country of 38 million people sees fewer than 2,000 legal abortions a year, but women's groups estimate that another up to 200,000 procedures are performed illegally or abroad.
An attempt by the PiS government to tighten the abortion law in 2016 was scrapped following nationwide protests by tens of thousands of women dressed in black.