Senate co-leader Jeff Klein and rival Oliver Koppell filed petitions Monday to square off in a key Democrat primary in September.
Klein (D-Bronx) said he's filed more than 9,000 petitions signatures - three times the number needed to get on the ballot. Koppell said he's filed 5,000. The district straddles Bronx and Westchester counties.
Candidates have to file petition signatures this week to attain ballot status.
Klein is the leader of the breakaway Independent Democratic Conference, which formed a coalition in 2013 with Senate Republicans to gain control of the chamber, to the chagrin of mainline Democrats. Klein and Gov. Andrew M. Cuomo -- after getting serious pressure from the liberal wing of the party -- recently announced the IDC planned to rejoin the regular Democrats after the November elections.
Not swayed, Koppell, a critic of Klein's move to align with Republicans, said he will still pursue a primary against the IDC leader.