Kwok accused the Electoral Affairs Commission of failing to state any clear standards for nominees’ eligibility.

In response, the commission reiterated it had no jurisdiction or role to play in the nomination process apart from providing support to the returning officers, who would make the decision. While these officers are appointed by the commission, they are civil servants.

Civic Party leader Alvin Yeung Ngok-kiu urged the government to quell doubts about how eligibility is determined to ensure a fair election.

But constitutional affairs minister Patrick Nip Tak-kuen on Wednesday rejected worries that the justice minister faced a conflict of interest in the matter.

“It is a safe and sound approach under the current mechanism,” Nip said. “The returning officer would work in accordance with the law and ask for relevant information from the nominees and seek legal advice from the Department of Justice when needed.”

Nip said he could not comment further as the nomination period was ongoing.

The camp agreed that the Democratic Party’s Ramon Yuen Hoi-man, who came third in the primary, would be the backup. Yet Yuen’s bid must still be endorsed by his party on Thursday night.

The pro-Beijing camp has endorsed Vincent Cheng Wing-shun for the race.

On Wednesday night it emerged that Yiu and Demosisto’s Agnes Chow Ting had written an open letter to electoral officers urging them to confirm their candidacies as soon as possible. Chow has signed up to run on Hong Kong Island, but is at risk of being barred over her calls for “self-determination” for the city.

The pair also raised concerns about the role of the justice department, arguing it had a conflict of interest and its legal advice should therefore not be taken into account.

Chow would run against Judy Chan Ka-pui.