Elected politicians in Mexico City voted Tuesday to allow women in the first three months of pregnancy to have abortions in the city.

The proposed legislation, approved by a vote of 46-19 with one abstention, would only apply within the capital, but it would mean women can travel to Mexico City to get legal abortions.

Anti-abortion activists protest in Mexico City Tuesday. Polls show a majority of Mexico City residents support legalizing abortion.
(Dario Lopez-Mills/Associated Press)

It is expected to take effect with the signing by the federal district's leftist mayor. Abortion opponents, however, have already vowed to appeal the law to the Supreme Court.

The law would require city hospitals to provide the procedure, but would also open the way for private abortion clinics.

Legislators who framed the bill said that girls under 18 would have to get the consent of their parents. Abortion after 12 weeks would be punished by three to six months in jail.

Supporters say hundreds of thousands of women get illegal abortions in the country every year.

Federal Mexican law allows abortion only in cases of rape, if the fetus has been deemed to have severe birth defects or if the pregnancy puts the mother's life at risk.

Polls show a majority of city residents support the legalizing of abortion but there is significant opposition to the measure.

Catholic bishops in Mexico have been speaking out against the move and anti-abortion protesters have held demonstrations, including candlelight vigils. With 90 per cent of Mexicans Roman Catholic, Mexico has the second-largest Roman Catholic population in the world after Brazil's.

The church has a lot of clout, said Maria Luisa Sanchez Fuentes, organizer of a group in favour of reproductive choice.

"They are extremely powerful and that has been one of the reasons why politicians had not considered [it] the right time to talk about abortion," she told CBC News.

Dr. Joel Lopez, part of an anti-abortion protest organized by the church, said he feels as though the battle against legalizing abortion is being lost.

"There's a plan, not just here in Mexico City, but worldwide," he said in Spanish. "It's being pushed by the World Health Organization and the UN, so abortion will be accepted all around the world. We are facing a very difficult situation."

In Latin America and the Caribbean, abortion is legal in Cuba and Guyana. Most countries in the region allow it in cases of rape or if the woman's life is at risk. Abortion is completely banned in Nicaragua, El Salvador and Chile.

With files from the Associated Press