Evan Vucci, File, Associated Press
In this May 1, 2014 file photo, Rep. Steve Israel, D-N.Y., chairman of the Democratic Congressional Campaign Committee, gestures during an interview with the Associated Press in Washington. Environmentalists, labor and women’s groups that spent more than $29 million to help House Democrats in 2012 have put up barely a quarter of that amount this year, sparking grumbling among party strategists that is likely to grow louder after Election Day.

WASHINGTON — Environmentalists, labor and women's groups that spent more than $29 million to help House Democrats in 2012 have put up barely a quarter of that amount this year.

That's sparking grumbling among party strategists that is likely to grow louder after Election Day.

Democrats, already in the minority, are in jeopardy of losing at least a dozen seats on Tuesday. An onslaught of outside Republican spending has overwhelmed incumbents once considered on track to re-election. The U.S. Chamber of Commerce, the Congressional Leadership Fund and American Action Network have spent nearly $10 million each targeting Democratic candidates and seats.

A desperate appeal from the chairman of the campaign committee two weeks ago for a late infusion of cash failed to sway the Democratic-leaning groups.