MANILA (2nd UPDATE) - A relentless Catholic Church campaign to derail a birth control law in the Philippines entered its final phase at the Supreme Court on Tuesday, with the verdict to have a monumental impact on millions of poor Filipinos.
The court began hearing arguments against a family planning law that President Benigno Aquino, defying intense church pressure, helped steer through parliament late last year.
It is the last legal recourse for the Church, which for more than a decade led resistance to birth control legislation in the mainly Catholic nation.
The Church, which had threatened Aquino and other supporters of the law with excommunication, held prayer vigils, protests and masses near the Supreme Court on Tuesday.
"We ask the Holy Spirit to enlighten and inspire the lawyers who would be arguing for our position... and enlighten the justices of the Supreme Court," Bishop Gabriel Reyes told a mass at a nearby church.
The law requires government health centres to hand out free condoms and birth control pills, benefiting tens of millions of the country's poor who would not otherwise have access to them.
More than a quarter of the Philippines' nearly 100 million people live on the equivalent of 62 cents a day, according to government data.
The law also mandates that sex education be taught in schools and that public health workers receive family planning training, while post-abortion medical care was legalised.
Proponents say the Reproductive Health law will slow the country's population growth, which is one of the fastest in the world, and reduce the number of mothers dying in childbirth.
"To deny RH services from our people would be a denial of human rights and a grave social injustice, especially against women and the poor," said Senator Pia Cayetano, one of the architects of the law.
The Supreme Court suspended the law in March so that the judges could hear the 15 formal petitions from a range of Church-backed groups arguing that it was unconstitutional.
The opponents argue it violates various elements of the constitution, including those on protecting the sanctity of the family and guaranteeing freedom of religion.
"It is a population control measure that denies the God-given right to reject contraception," Franciso Tatad, a former senator representing the petitioners, told the Supreme Court judges in opening remarks.
The Church wields strong influence in the Philippines, a former Spanish colony where roughly 80 percent of the population remain Catholic.
Church leaders have helped lead two revolutions that toppled unpopular presidents in recent Philippine history, and continue to insist they have a right to influence the parliamentary and legal branches of government.
"When the rights of mother and child are endangered, when the family is being attacked, you can expect the Church to speak up," Catholic Bishops Conference of the Philippines head Bishop Socrates Villegas said on Monday.
A crowd of about 400 opponents of the Reproductive Health law gathered outside the Supreme Court as the judges began hearing the case, holding banners such as: "Obey God's will, no to RH bill".
Another read: "RH Bill is abortion".
They stood on the other side of the road from a smaller crowd of supporters of the law, some of whom carried a banner that read: "Rights and welfare, not the beliefs of a few".
Opinion surveys over many years have shown strong public support for birth control legislation.
And despite criticism from church leaders, Aquino enjoys near record-high popularity ratings half way through his six-year term.
It was unclear on Tuesday how long the legal proceedings will take or when the Supreme Court will make a decision.
Lawyers involved said a verdict could be months away.