MANILA (REUTERS) - Four of the Philippines' presidential candidates on Saturday (Jan 22) laid down plans to tackle the country's biggest issues in interviews with the nation's leading broadcaster, but notable was the absence of early front runner Ferdinand Marcos Jr.

Mr Marcos, a clear favourite for the May 9 presidential election, declined to participate, saying the host was biased against him, a charge GMA Network strongly denied.

The pre-recorded interviews, which ran for three hours, set social media ablaze.

There was some harsh criticism of Mr Marcos, with thousands on Twitter using the hashtag marcosduwag (marcoscoward), while praising other candidates and the host.

Mr Marcos, 64, the only son of late dictator Ferdinand Marcos Sr, said he will communicate his message through other shows, platforms and forums.

Political analysts credit Mr Marcos' active social media presence for his strong showing in polls, but some suggested it might not be enough.

"Should the Marcos camp continue to shun these kinds of nationwide events, it is possible, if not highly probable, that... the second preferred candidates can pick up some numbers," said Mr Richard Heydarian, an author, columnist and academic who specialises in politics.

Retired boxing champion Manny Pacquiao, Vice-President and opposition candidate Leni Robredo, Manila city mayor Francisco Domagoso and former police chief Panfilo Lacson presented their plans for a post-pandemic economic recovery through job creation, better health care and fighting corruption.

"What we need is a clean government, without corruption, and with plans to give jobs and housing," Mr Pacquiao said.

The Philippines, a country of more than 110 million people, will select a successor to President Rodrigo Duterte, who is not eligible for re-election, in May.

All of the candidates tried to differentiate their policies from those of Mr Duterte, from handling the narcotics problem to tackling a maritime dispute with Beijing.

All four said they would not support the reimposition of the death penalty or the legalisation of same-sex marriage, but they were divided on divorce - a touchy issue in Asia's most Catholic country.

In the Philippines, personality politics dominates platforms.

Twitter has suspended hundreds of accounts that were promoting Mr Marcos, citing violation of rules on spam and manipulation.