The pro-abortion lobby is challenging Catholic tradition

Currently abortions are only legal in Portugal if a woman has been raped, if her life is in danger, or if the baby has serious abnormalities.

But the governing Socialist Party is proposing that women should be allowed to choose an abortion up to the 10th week of pregnancy.

The public vote is expected to be set for January.

It was proposed by the governing Socialists, and backed by the main opposition centre-right Social Democrats and the far-left Left Block.

The Communist party voted against, while the Christian Democrats abstained.

Illegal terminations

Prime Minister Jose Socrates has said he wants to end the situation where the abortion ban leads to women having illegal backstreet terminations.

"The party wants the sore of illegal abortions to cease to exist because it is a sign of a backward country," he said.

Campaigners say that while rich women can afford to go abroad for abortions, thousands of poor women end up in hospital each year after resorting to backstreet operations.

Opponents of abortion in the mainly Roman Catholic country argue that an unborn child should be protected as forcefully as a born one.

The last referendum on the subject, in 1998, was defeated when large numbers of people boycotted the vote, making the result invalid.

Portugal has some of Europe's most restrictive abortion laws.