The bishops, in the letter read at Masses June 7, also sought to remind the voters that voting was not merely a political right, but "a moral obligation," reported the Asian Catholic news portal ucanews.com.

"While politicians plan and strategize (and) find ways of circumventing the law against premature campaigning, the church cannot be remiss in its obligation of forming the consciences of Catholic and Christian voters," the bishops said in the letter, which was signed by Archbishop Socrates Villegas Lingayen-Dagupan, president of the Catholic Bishops' Conference of the Philippines.

The letter called on the public to "vote for the right reasons ... not because you have been paid ... but because you trust a person to lead the community and to lead the country."

The bishops also urged voters to end political dynasties by not voting for candidates from the same family who want to perpetuate their family's hold on public office.

"There is no monopoly on ability for government, and truly no one in government is indispensable," the bishops said.

The letter cited criticisms that previous church efforts to educate voters had come too late to be effective.

"It may never be again said that we spoke too late," the letter said.

The bishops also warned the electorate not to jump to conclusions "in the absence of incontrovertible evidence."

"These days, one's reputation, so painstakingly built by sincerity and honesty over the years, can so easily be tarnished by the truly evil work of 'spin-doctors' in the payroll of one or the other political aspirant," the letter said.

Church leaders in May launched a campaign against "vote buying" and "vote selling," dubbed "Thou Shall Not Steal."

In 2013, the country's Catholic bishops questioned the results of national elections after reports of rampant vote fraud.

The bishops' National Secretariat for Social Action said later that those elections made "a mockery of the country's democracy." The bishops noted that although the elections were relatively peaceful, there were "glaring discrepancies and election violations."