The debate is harsh and emotional, showing that for all the changes Jose Luis Rodriguez Zapatero has introduced with his trailblazing social agenda since taking power in 2004, abortion remains ever sensitive in a country where most people call themselves Catholic, even if few churches are full on Sundays.

Liberalizing teen abortion is part of a broader reform proposed for Spain's abortion law, the main thrust of which is to allow the procedure with no restrictions up to 14 weeks into a pregnancy.

The government gave the bill preliminary approval in May and Parliament is expected to take it up in the fall. Zapatero probably has the votes to get it passed. However, the outcry on the teenager issue may force him to backtrack.

Under the current law, Spanish women can in theory go to jail for getting an abortion outside certain strict limits _ up to week 12 in case of rape and week 22 if the fetus is malformed. But abortion is in effect widely available because women can assert mental distress as sole grounds for having an abortion, regardless of how late the pregnancy is.

Now Zapatero is seeking to deepen his mark on Spanish society. What he's proposing wipes away the threat of imprisonment and declares abortion to be a woman's right.

"That is a qualitative change in Spanish culture and politics," said Javier del Rey, a professor of political communications at Complutense University in Madrid. "Something that had been a crime is transformed into a right."

Britain, France and Germany already allow minors to get abortions without parental permission. But here it's the issue that is dominating the debate.

The conservative opposition Popular Party asks why a girl who cannot legally buy alcohol can have an abortion without asking her parents. "The inconsistency is crushing," lawmaker Sandra Moneo wrote in the newspaper El Pais.

"No father or mother can understand the idea of a minor going through that trauma without the advice, support and opinion of her parents," Moneo said.

Zapatero's camp counters by noting that 16-year-old Spaniards can choose to have open-heart surgery or chemotherapy without parental consent, but not an abortion.

Tempers have flared on both sides. Conservatives were enraged when Bibiana Aido, the minister of equality, suggested abortion was no bigger an issue than breast enlargement.

Socialists saw red when Antonio Canizares, a Spanish cardinal who holds a key position at the Vatican, seemed to play down a report detailing decades of sexual and other abuse of children by religious orders in Ireland and said abortion was worse.

Zapatero himself was asked in a radio interview how he would feel if his daughter, after she turned 16, had an abortion without telling him.

Zapatero said he would rather she tell him, and that it was up to parents to instill that kind of trust in their kids.

"But in the end, the decision is up to the person deciding whether to voluntarily interrupt a pregnancy," the premier said.

Polling numbers are against him: a survey published last month by the newspaper La Vanguardia said 71 percent oppose the teenage abortion reform, and the proportion among Socialist voters was 60 percent. A poll in El Pais put the figures at 64 and 56 percent, respectively. Both surveys gave a margin of error of 3.2 percentage points.

Lawmaker Carmen Monton, the Socialists' point woman on the abortion bill, said it was designed to help girls from troubled families who need an abortion and cannot tell their parents.

"We are not legislating for model families with fantastic relations between parents and children. We are legislating for all of society," Monton said in an interview.

Josefina Elias, president of the polling firm Instituto Opina, said she would not be surprised if Zapatero withdraws or tones down the proposal, and some suspect he put it forward to serve as something he can concede if necessary to win passage of the broader reform.

One idea already being floated is to oblige teens to tell their parents they plan to have an abortion, although not to obtain permission.

Elias said Zapatero's mistake was to undertake the reform without any prior social debate about teen abortion.

"It has all been done like an elephant charging into a china shop," she said.