The Catholic Church in the Philippines has raised the stakes in its fight against the historic birth control bill passed in December by the legislature, seeking to use the ballot box in May 13 general elections to go directly after lawmakers who voted for the measure.

The midterm election will see 12 senators and 229 members of the House of Representatives as well as governors, provincial legislatures and mayors facing the voters. The church's decision to publicly oppose those who voted for the reproductive health act, as it is known, may be the church's biggest gamble of its influence in modern history.

"The results of the May 2013 election will likely illustrate to what extent the Catholic Church's political agenda resonates with both voters and politicians," according to a subscription-only report by the Manila-based country risk firm Pacific Strategies & Assessments. "While the outcome of the elections are unlikely to impact the church's popularity, it could affect the church's political agenda."

Victories by pro-birth control candidates, the report said, could suggest a decline in church influence and encourage politicians to push for passage of legislation the religious body opposes, such as a proposed divorce law that has been stalled in the legislature for decades. The Philippines is the only country in the world that hasn't legalized divorce.

Conversely, if the church holds sway and drives lawmakers from office, other legislation proposed by President Benigno S. Aquino III including land reform and the regulation of the mining industry could be affected negatively.

The Conference of Bishops, the church's ruling body, has already mounted an all-out legal campaign against the reproductive health act, which Aquino signed into law in January. Ten different petitions have been filed with the Supreme Court by allies of the church to attempt to stop the law from going in effect. The court, on March 19, voted to delay implementation of the measure until oral arguments are held on June 14.

The law mandates that government health centers provide free access to nearly all contraceptives including condoms, IUDs and other devices to everyone. It also makes sexual education compulsory in public schools.

The electoral focus of the church's campaign so far has been the city of Bacolod, with 511,000 residents, the capital of Negros Occidental Province in the Western Visayas Region. In February the Bacolod Diocese posted a giant tarpaulin in front of the San Sebastian Cathedral, listing the names of lawmakers who had voted for the bill and calling them "Team Buhay," or "Team Death." Lawmakers who voted against it were identified as "Team Patay," or "Team Life."

At least 60 churches in the diocese have posted smaller Team Patay posters in the effort to oust lawmakers who voted for the legislation. Political observers have described the effort by the church as unprecedented in Philippine politics. In the past the church has never campaigned against candidates by name, instead listing the traits voters should look for in candidates.

The Bacolod campaign almost immediately ran into heavy going from a group calling itself "Team Tatay," or "team father," identifying five Bacolod priests including three bishops, an archbishop, a retired bishop and one priest who allegedly have sired children. Married priests have long been a widely suspected phenomenon in the Philippines. Indeed, Team Tatay said it would unmask further married priests if the Team Patay campaign continues.

Undeterred, another five dioceses are said to be planning to join the Bacolod campaign. According to the news site Rappler, they are in Marinduque, Occidental Mindoro, Bulacan, Laguna and Batangas, three of them among the country's most populous provinces.

The church's influence in the past played a major role in ousting the strongman Ferdinand Marcos in 1986, when he was forced to flee the country in the so-called People Power revolution which brought millions of Filipinos to the streets to protest his policies. The church also played a major role in driving Joseph Estrada from power in 2001 after he was accused of corruption and an impeachment campaign against him failed.

However, the church's gamble in the May elections could be chancy. Although 81 percent of Filipinos classify themselves as Catholics, as many as seven of 10 polled indicated they supported the passage of the reproductive health act, according to Rom Dongeto, the executive director of Philippine Legislators' Committee for Population and Development (PLCPD), an NGO that is one of the strongest proponents of the law. Half of Filipinos who marry today do so in civil ceremonies, or don't wed at all, which fits with statistics that show 20 percent of the country's births are out of wedlock.

It might be ominous for the church that the Conference of Bishops last year mounted an all-out campaign when it became clear that Aquino would attempt to push through its passage, with parish priests all across the country denouncing the measure from the pulpit on a weekly basis.

Apparently the flock didn't get the message. They certainly didn't turn on the President. Despite the church's campaign, Aquino pushed the bill through with relative ease. And, despite threats - not carried out - by the church to excommunicate the president, he remains extremely popular with the voters. In the latest Pulse Asia survey, his overall rating climbed from 66 percent in January to 68 percent today, with his undecided rating falling by four points. Getting their parishioners to vote to drive his political allies from office may be more difficult than church leaders think.