Albert Ho Chun-yan's attempt to challenge the chief executive's election victory was blocked yesterday by the High Court, which refused to extend a critical deadline.
Mr Justice Johnson Lam Man-hon dismissed Ho's election petition, refusing to extend the deadline for filing the challenge, which is seven working days after the results of the March 25 election were announced.
Ho's challenge - against Chief Executive Leung Chun-ying's victory - missed the deadline by several months.
The former Democratic Party chairman, who finished third in the election, Ho has argued that Leung was not duly elected because he made false statements about illegal structures during his campaign.
The judge said Ho's case had little merit.
"Since Mr Ho's case has no real prospect of success, it would not be in the interest of justice to grant him an extension of time," Lam wrote in his judgment, handed down yesterday.
Ho said he was disappointed with the judgment. He planned to consult his legal team and his party before deciding whether to file an appeal.
"This is a matter involving huge public interest," he said. "Certainly I hope that there will be a hearing."
Central to the petition is whether Leung made a false statement when he attacked election rival Henry Tang Ying-yen during a televised debate over illegal structures at Tang's Kowloon Tong home.
Ho claims that by criticising Tang, Leung implied he himself had made no unauthorised alterations to his own house. In June - almost three months after Leung won the election - the media exposed six unlawful structures at his home.
The judge, however, described it as a "quantum leap" to take Leung's attack as a statement about properties owned by Leung.
"Irrespective of what [Leung] had done or said prior to his public declaration of intent, so long as he did not make any statement about the lack of [unlawful building works] at his properties after his declaration [of candidacy] on 27 November 2011, there is no viable challenge under [the relevant law]," Lam wrote.
Lam ruled that a reasonable person would not understand Leung's attack at Tang as an implicit statement about himself.