The scandal-scarred Democrat hoping to lead the US’ largest township is suing it, accusing GOP leaders of illegally installing his November opponent to the post — after the current seatholder abruptly stepped down.

Joseph Scianablo, the Democratic hopeful running for Hempstead supervisor, is slamming town Republicans for staging a “backroom deal” — in violation of the state’s open meetings law — to appoint John Ferretti to the seat after Supervisor Don Clavin resigned in the middle of a board meeting earlier this month, a lawsuit filed Monday claimed.

“What happened in the Town of Hempstead is not democracy,” Scianablo told reporters moments after filing the suit in Nassau Supreme Court. 3

Scianablo and Ferretti, a former Nassau County legislator, are set to square off on Nov. 4

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