"Alex Morse's record isn't inspiring. It's brutal," the narrator said in a one-minute spot. “Since becoming mayor, multiple police brutality lawsuits have been filed against his police department, and Alex Morse remained silent."

The ad flashes quotes from the lawsuits describing alleged incidents — including one in which a 12-year-old boy was beaten — and knocks Morse for not calling for investigations.

American Working Families describes itself as an organization dedicated to “fighting back against the war on working people” and opposed to “corporations who promote hyper-partisan agendas.”

The group did not disclose the full size of the buy, but Chris Keohan, a spokesperson, said it plans to match the spending of any organizations backing Morse or opposing Neal.

Progressive operatives formed a new initiative, Fight Corporate Monopolies, in early July to blast politicians who they feel are too cozy with corporate interests. Neal is their first target, and they vowed to spend at least $300,000.

The anti-Neal first ad accuses him of being in the pocket of a private equity firm that is accused of profiting off surprise medical billing.

The left is eager to take down another House chair after middle school principal Jamaal Bowman ousted House Foreign Affairs Chair Eliot Engel in a June primary. And by the time New York is done counting ballots from the June 23 primary, liberals may have snatched another victory. Carolyn Maloney, the chair of the House Oversight Committee, is locked in a tight battle with Suraj Patel.

Morse is the youngest and first openly gay mayor of the city of Holyoke and has nabbed endorsements from key progressive groups like Justice Democrats and the Sunrise Movement. The district spans Western Massachusetts and is safe Democratic territory.

Neal was first elected in 1988 and had over $4.2 million in his campaign account by the end of June. Morse had $315,000. But his campaign announced Monday that he had raised more than $1 million since launching his bid.