Marcos Jr, son and namesake of the country’s former dictator, has snubbed invitations to participate in debates with rivals, rarely gives media interviews and often ignores journalists’ questions at rallies.
He has sought to avoid a repeat of the 2016 vice-presidential race, when he was hounded over questions related to his father’s violent and corrupt rule.
The younger Marcos narrowly lost that contest to Robredo and spent five years trying to have the result overturned.
In this campaign, Marcos Jr was the only candidate out of 10 hoping to succeed president Rodrigo Duterte to skip the two televised debates held by the government’s Commission on Elections.
He also refused to attend a debate hosted by CNN Philippines.
“I am therefore inviting Bongbong Marcos to a debate, to give the Filipino people a chance to face him and ask him questions, particularly those regarding the many controversies surrounding him,” Robredo said in a statement, using Marcos Jr’s nickname.
“We owe it to the people and to our country. If he agrees, anytime, anywhere, I will be there.”
Marcos Jr’s spokesman Vic Rodriguez said the “debate will never happen for a number of reasons”, without elaborating.
“We address the public directly in communicating our message of unity,” Rodriguez said, accusing the opposition camp of “negativity, deception and criticism”.
Marcos Jr previously told a journalist he would no longer “return to 35-year-old issues”, referring to allegations that his father presided over theft from state coffers and human rights abuses.
In a rare interview with CNN Philippines this week, Marcos Jr said: “I don’t know why they say it’s difficult to ambush interview me. I’m always out in public.”
Marcos Jr has a massive social media campaign, including YouTube videos that seek to portray him and his family as regular people.
Pro-Marcos groups have also flooded Facebook with fake and misleading posts to revamp the family’s image and smear main rival Robredo.
Voter surveys show Marcos Jr has a huge lead over Robredo.
A recent bump in the polls, however, has given Robredo’s supporters hope that their volunteer-driven campaign is gaining traction.