ISLAMABAD, Pakistan — Pressure is mounting on Pakistan's president, Asif Ali Zardari, to pardon a Christian woman sentenced to death for blasphemy in a case that has attracted unprecedented attention in this Islamic republic.

The governor of the province where the blasphemy allegedly took place said he would present Zardari with a petition for mercy on behalf of Asia Bibi, a 45-year-old field worker who is accused of having insulted Prophet Muhammad and was sentenced to death by hanging earlier this month.

Separately, Shahbaz Bhatti, the minister for minorities, said he would submit a report to Zardari on Wednesday with recommendations for the president on which actions to take on Bibi's case. In an interview at his office in Islamabad, Bhatti declined to elaborate on the recommendations he planned to make to the president, but he made no mystery of his feelings on the case.

"This is a baseless, concocted story," Bhatti said. "No blasphemy was committed by Asia Bibi."

Blasphemy cases are common in Pakistan, but few have caused such a stir. Several foreign leaders have condemned Bibi's conviction, and Pope Benedict XVI called for her release. Pakistani human rights groups and some newspapers have taken up her cause, but it is the involvement of high-level politicians that is novel in this conservative Muslim country.

A blasphemy law has been on the books since the British India era but only a handful of cases resulted in convictions during that time. It was only after the government of Muhammad Zia-ul-Haq passed a set of stricter blasphemy laws in the early 1980s that the number of cases ballooned.

Over the past 30 years, about 4,000 cases were registered and about 700 of them led to convictions, said Husain Naqi, an official with the Human Rights Commission of Pakistan.

Disrespecting Prophet Muhammad is punishable by death, while less serious offenses carry jail sentences. No one has been executed under the blasphemy laws to date, but activists say some accused of blasphemy have been murdered by mobs and assassins, sometimes with the connivance or indifference of the authorities.

Earlier this month Imran Latif, a 22-year-old man who had been accused of blasphemy and released on bail, was shot dead near his home. A police officer investigating the case said that Muslims should not tolerate those who commit blasphemy.

"If a law enforcer can justify a murder on this pretext, it means that we are officially sanctioning a free hand to murderers," wrote the Daily Times, a local newspaper, in an editorial. "When our policemen pass such intolerant statements, we should not expect much from the bigots present in every nook and corner of this (un)blessed land."

Some blasphemy cases concern Muslims, but most of those accused belong to religious minorities. The main targets have been Christians and Ahmadis, members of a religious movement that believes in a prophet after Mohammad and is not considered Muslim by Pakistanis.

"My personal analysis is that this law is a tool in the hands of extremists to victimize the minorities of Pakistan," Bhatti said.

Even though opponents of the blasphemy laws are gaining momentum, opposition to a repeal of the laws is likely to be much stronger.

"These laws are brought in the name of religion, so it's really hard to repeal them in a society with 96 percent of Muslims," said Babar Sattar, an Islamabad-based lawyer.

Short of an outright repeal of the laws, some advocate amending them to curtail abuses. Proposed measures include having magistrates conduct an investigation before a case is lodged and punishment for those guilty of bringing false accusations.

In any case, these legal changes would come too late for Bibi, a mother of five who was arrested in circumstances that remain murky. She was working with a group of Muslim women in her village in Punjab when she was accused of soiling the water of a well by drinking it. An argument followed in which she was said to have insulted Prophet Muhammad. A mob quickly gathered, and a complaint was later filed by a local Muslim cleric.

Bibi has denied ever committing blasphemy, and Bhatti, who met with her relatives and conducted his own investigation, said there are many gaping holes in the case, including the fact that the complainant never witnessed the alleged blasphemy act. Bhatti, himself a Christian, said he believed Bibi was accused of blasphemy because she refused to succumb to pressures from villagers who wanted her to convert to Islam.

Bibi's conviction can still be reversed in a higher court, but after spending 15 months in prison, the shortest path to freedom goes through the president's office. Zardari has not commented publicly on Bibi's case, but Bhatti said he was hopeful the president would come to Bibi's rescue.

"I think President Zardari is a progressive and liberal leader of this country," Bhatti said. "I think he will stand for justice for this innocent lady."