President Barack Obama faces waning enthusiasm from union members as he prepares for his 2012 re- election bid, AFL-CIO President Richard Trumka said.

"It will be more challenging this time than it was last time to motivate our members," Trumka, 61, said in an interview today at Bloomberg's offices in Washington.

Trumka, head of the largest U.S. labor organization, said union members are frustrated by "wasted energy" in Washington on issues that he said don't help workers: "hysteria" about the federal deficit, a White House review of regulations and Obama's support for free-trade agreements.

Labor leaders said in recent weeks that they would withhold financial support in next year's election from candidates who haven't sided with unions consistently, a move that may hurt Democrats who have relied on labor backing. The International Association of Fire Fighters has vowed to withhold campaign money from federal races, throwing its money into state-level campaigns.