Poland's rightwing government has delayed implementation of a controversial court ruling that would outlaw almost all abortion in the country, after it prompted the largest protests since the fall of communism.

"There is a discussion going on, and it would be good to take some time for dialogue and for finding a new position in this situation, which is difficult and stirs high emotions," Michał Dworczyk, the head of the prime minister's office, told Polish media on Tuesday.

The decision by the country's constitutional tribunal promised to further tighten Poland's abortion laws, which were already some of the strictest in Europe. The tribunal ruled that terminations should be illegal even in cases where a foetus is diagnosed with a serious and irreversible birth defect. This kind of abortion accounts for almost all of the small number of abortions performed legally in the country.

The decision has still not been published, despite a Monday deadline, and as such has not entered into force. "It's clearly a political decision," said Anna Wójcik, a researcher at the law studies institute at the Polish Academy of Sciences. "Judgements are meant to be published with no delay. It's a legal trick to withhold publishing."