State GOP chairman Ed Cox, who previously called on Silver (D-Manhattan) to step down, said he's trying to up the pressure on the speaker.
Silver approved a $135,000 payment -- $103,000 of it in public money -- to settle sexual harassment allegations against Lopez (D-Brooklyn). Silver has said he mishandled the case by not referring the charges to an Assembly ethics panel -- as he did with subsequent allegations against Lopez.
The case has sparked a civil probe by the state Joint Commission on Public Ethics and a criminal investigation by a special prosecutor.
Republicans blasted Silver not only for settling the first case confidentially but also for waiting to disclose it until after the second set of sexual harassment allegations became public. After the second case, Silver censured Lopez, reduced his staff and took away a lucrative committee chairmanship.
But Cox said that wasn't enough.
"Faced with a member of his caucus who had on multiple occasions sexually harassed female staff members, Speaker Silver neglected to refer the matter to the [ethics committee] and instead took an active role in covering up the abuse," Cox said. "He did not do something in those first cases -- he made them go away. He sets the tone for the entire Assembly. Therefore, he must step down."
Silver spokesman Michael Whyland countered that Cox's call was "nothing more than election year politics."
Whyland noted that Silver's Republican counterpart in the Assembly, Minority Leader Brian Kolb (R-Canandaigua), hasn't called on the speaker to resign.
Silver and numerous other politicians and activists have called on Lopez to step down. He has refused.
Silver has said he'd welcome an investigation into the settlement because it would show the agreement "was both legal and ethical and made out of deference to the wishes of the complainants."
"For him to say he acted ethically," Cox said, "is a bald-faced misstatement at best."