Over 100,000 people in 90 Polish cities took to the streets Monday to protest proposed pro-life legislation that would protect children in the womb by criminalizing abortions in the Eastern European country.

Organizers encouraged women to go on strike in order to join the nationwide rally, which spilled into “solidarity” gatherings in other cities around Europe.

Abandoning their offices, classrooms and homes to march for the right to kill unborn children, participants called it Black Monday. Smaller protests were happening even before Monday.

The proposed legislation would take Poland’s laws one step closer toward protecting all lives in the womb. The existing “abortion compromise” law, passed in 1993, only allows abortion in the first 12 weeks of pregnancy, and only in cases of rape or incest, if the baby is severely deformed or if the mother’s life is in danger.

The new law, if passed, would make abortion illegal, and doctors who perform abortions could be sentenced to up to five years in prison. The only exception would be if the baby’s life were unintentionally lost during a procedure to save the mother’s life.

Officials estimate that 1,000 legal abortions take place in Poland per year. And though estimates vary between pro-life and pro-abortion groups, the consensus is that the number of illegal abortions is much higher.

Barbara Nowacka, a leader of a pro-abortion organization called Save Women, called the new proposal aimed at saving unborn lives “barbarian,” telling The New York Times it would “move Poland back to medieval times.”

The Catholic Church in Poland has publicly supported the bill, which was proposed in late September.

According to Polish Bishop Marek Jedraszewski, “black protests are a terrifying manifestation of the civilization of death.”