The nation's fastest growing labor union just got bigger.

WASHINGTON — The nation's fastest growing labor union just got bigger.

About 150,000 breakaway members of the trade union UNITE HERE have formed a new organization and say they will affiliate with the Service Employees International Union.

The influx of textile, restaurant and hotel employees will push SEIU's membership to nearly 2.2 million workers.

UNITE HERE was the product of two unions that merged five years ago — the Union of Needletrades, Industrial and Textile Employees, known as UNITE — and the Hotel Employees and Restaurant Employees International Union. But a culture clash produced months of infighting that divided its roughly 400,000 members.

The dissident workers, after meeting at a convention in Philadelphia over the weekend, are calling their new union Workers United. Their move was spurred by UNITE HERE president Bruce Raynor, the former head of UNITE, who blames the split on organizational failures and has been urging a breakup.

Some critics contend SEIU president Andy Stern encouraged the rift by luring the breakaway group to join his union, a charge Stern denies.

"Sometimes mergers don't work," Stern said. "This is the poster child of a well-intentioned effort that didn't succeed for the workers."

Stern said the workers realized "what we've been able to do on a much larger scale for security officers, janitors and home care workers — trying not to organize one employer or one city at a time, but whole sections of industries at a time."

The new union's president, Edgar Romney, agreed that workers wanted to affiliate with SEIU given its record of success in expanding the labor movement.

"We decided we needed to do something, we needed to move forward because it wasn't happening under the old UNITE HERE," Romney said.

But John Wilhelm, president of UNITE HERE's hospitality division, and an opponent of the split, called the move "a transparent ploy to justify (Stern's) hostile takeover of UNITE HERE jurisdiction."

Wilhelm and his supporters have argued that the union's constitution bars members from leaving and he has gone to court in an effort to prevent them from leaving.

Romney said the new union's lawyers assured him "we're on solid legal footing" in terms of moving forward.