WASHINGTON – A major labor union and an outside group committed to electing Democrats to the House have reserved nearly $20 million in television ad time for the fall in districts from Illinois to Florida as the party tries to reclaim the majority, The Associated Press has learned.

House Majority PAC, a so-called super political action committee that recently helped Democrats hold former Rep. Gabrielle Giffords' Arizona seat, is investing $16 million, while the 2.1 million-member Service Employees International Union is spending $3.7 million, according to an official from the Democratic-leaning group who described planned spending. The official spoke on condition of anonymity to freely discuss the plans.

The ad reservation targets at least 47 competitive House races that include vulnerable Republican incumbents as well as Democratic lawmakers facing strong challenges.