Philippine social media has exploded with support for presidential election favorite Ferdinand Marcos Jr, driven by a massive misinformation campaign aimed at revamping the family brand and smearing his top rival.

False and misleading claims have flooded Facebook, YouTube, TikTok and Twitter in the lead-up to the May 9 polls, pounding Filipinos with a barrage of propaganda on platforms where they rank among the heaviest users in the world.

Surveys show the son and namesake of the dictator heading for a landslide victory - the endgame of a decades-long, well-funded effort to return the family to the presidential palace they fled in disgrace in 1986.

Critics and opponents accuse Marcos Jr and his supporters of trying to portray his father's two-decade rule as a golden age of peace and prosperity while whitewashing human rights abuses and the plundering of state coffers.

And the effort to make over the family's image appears to be translating into votes among the largely young electorate and those nostalgic for the Marcos years.

Election-related misinformation has focused on frontrunners "Bongbong" Marcos Jr and Vice President Leni Robredo.

Data show Robredo, 56, reeling from preponderantly negative messages and Marcos Jr, 64, enjoying overwhelming positive ones, say Maria Diosa Labiste and Yvonne Chua of fact-checking alliance Tsek.ph. They said the trend was reminiscent of the flood of posts about current president Rodrigo Duterte and his opponents in 2016 that were seen as key to his win.

Marcos Jr draws support from the family's northern stronghold as well as his alliance with vice presidential candidate and first daughter Sara Duterte.

But social media's influence is critical.

One major battleground is Facebook, used by most of the Philippines' 76 million internet users.

Since Marcos Jr's narrow loss to Robredo in the 2016 vice presidential race pro-Marcos pages have pumped out misinformation about everything from electoral fraud and the family's wealth to economic achievements during his father's rule.

Robredo, who trailed Marcos by 45 percentage points in the latest poll by Pulse Asia Research, has been a major target.

Among dozens of claims about the Marcoses debunked by fact-checking is the popular assertion that the patriarch made his fortune when he was a lawyer via a massive gold payment from a client.

Also fact-checked were dozens of false or misleading claims about Robredo, including doctored photos and videos that aim to portray her as stupid, unfriendly toward voters or a communist.

In the past year there have been nearly 75 million interactions - reactions, comments or shares - with posts on more than 100 pro-Marcos pages with at least 3,000 followers, according to social media monitoring platform CrowdTangle.

That compares with just over 39 million interactions for the same number of pages promoting Robredo.

When Robredo announced her presidential bid on October 7 interactions on pro-Marcos pages spiked to more than 1.8 million - about nine times the daily average. Pro-Robredo pages received 487,000 interactions.

"It's hard for the other campaigns to compete with the Marcos machinery online because this is six years in the making," says Cleve Arguelles, an assistant lecturer in political science at De La Salle University in Manila. "They've really worked hard to dominate these spaces, and they're reaping the benefits of investing early in troll armies and building online communities."

In January, Twitter suspended more than 300 accounts reportedly linked to supporters of Marcos Jr, which the social media giant said violated its rules on manipulation and spam.

Marcos Jr has denied using trolls. "I am the victim of fake news as there are many things said about me that are not true," he said.

Marcos Jr's social media strength is the result of a "long-term investment" to rehabilitate the family brand, says Jonathan Corpus Ong, a disinformation researcher at the University of Massachusetts and Harvard University.

After the fallen dictator's death in 1989 his heirs returned home and began their remarkable political comeback, getting elected to public office while distancing themselves from their past.

Members of the clan are often portrayed as victims in misleading posts claiming they receive unfair treatment from mainstream media -- akin to claims by former US president Donald Trump.

To combat misinformation, Facebook says it works with the Commission on Elections to "connect people with accurate election information" as well as supporting fact-checking activities and investing in education programs.

But Maria Ressa, a Nobel Peace Prize-winning journalist and cofounder of Philippine news site Rappler, says Facebook could do more to "help bring down the lies."

She argues: "You cannot have integrity of elections if you don't have integrity of facts. If they make the facts debatable they are essentially dooming our nation."

Despite being villified as a tax evader, Ferdinand Marcos Jr is ahead of Leni Robredo.

Filipinos fall for fake history