>Brooklyn Councilman Ari Kagan is expected to switch his party affiliation from Democrat to Republican on Monday — and announce a general election challenge against one of his Democratic colleagues, three sources familiar with the matter told the Daily News.

>Kagan, who was first elected in 2021 to represent Coney Island and other southern Brooklyn neighborhoods, is set to officially declare he’s becoming a Republican during an afternoon press conference at City Hall, said the sources, who spoke on condition of anonymity.