Philippine election candidates will hit the hustings Tuesday for the official start of campaigning, with the son and namesake of former dictator Ferdinand Marcos leading the presidential race as he seeks the ultimate revival of the family brand.

Political scions, celebrities and ex-convicts are among the contenders vying for more than 18,000 posts in the May 9 polls, with most interest on the contest to succeed authoritarian firebrand Rodrigo Duterte, whose six-year presidency has been marked by foul-mouthed tirades and a deadly drug war.

More than 35 years after the Philippines emerged from his father’s dictatorship, voter surveys show Ferdinand Marcos Jr heading towards a landslide victory as a massive social media campaign cranks up support and, critics say, whitewashes the clan’s history.

Boosted by a formidable alliance with first daughter and vice-presidential candidate Sara Duterte, Marcos Jr – one of the most polarising figures in the Philippines – has vowed “to unify the country and give our fellowmen the future that they deserve”.

In the Philippines, the president and vice-president are elected separately.

Efforts to disqualify Marcos Jr over a decades-old tax conviction sparked a public spat between election officials, while allegations of cocaine snorting and corruption among presidential candidates have fuelled a political atmosphere of chaos and skulduggery.

As usual, personality will trump politics for many of the roughly 65 million voters deciding who to support.

“This will be a campaign dominated by personalities and political dynasties, rather than a contest over policies or economic ideologies,” said Eurasia Group analyst Peter Mumford.

Outgoing presidents usually identify their preferred successor, who they hope will keep them out of prison as much as protect their legacy.

But Duterte has been silent since his choice, loyal aide Senator Christopher Go, pulled out of the contest.

Polls show Marcos Jr, popularly known as “Bongbong”, with a huge lead in a field of five credible candidates for president.

Some analysts are still cautious about calling a winner in a race that only requires the victor to get more votes than anyone else.

Vice-president Leni Robredo – the opposition candidate and nemesis of both Marcos Jr and Duterte – is a distant second, ahead of celebrity mayor Francisco Domagoso, retired boxing champion Manny Pacquiao and ex-police chief Panfilo Lacson.

“Nothing is set in stone – it’s a very fluid race,” political analyst Richard Heydarian told a briefing.

Victory for Marcos Jr would mark the ultimate political comeback for his controversial clan, which was chased into US exile after the patriarch’s humiliating downfall in 1986.

The dictator oversaw widespread human rights abuses to maintain his control of the country and enable his massive plundering, with thousands of people killed or tortured, previous Philippine governments said.

Opponents seeking to block the Marcos family’s return to the presidential palace have filed petitions with the Commission on Elections to have the son thrown out of the race over a previous conviction for failing to file income tax returns.

He has already beaten one of the challenges, but a key ruling on several disqualification cases has been delayed.

One of the election officials involved in hearing those cases retired last week – but not before she broke ranks and published her decision to disqualify Marcos Jr and lobbed accusations of political interference.

“I think there’s enough wiggle room to actually let him off,” said a long-time observer of Philippine politics.

“This country would probably explode if Bongbong Marcos was disqualified.”

Marcos Jr has tried to defend his father’s rule by citing economic growth, and minimised the human rights abuses during that regime.