A majority of union members now work for the government, partly because massive layoffs in the recession plunged the private sector's union levels to a record low.

Local, state and government workers make up 51.5 percent of all union members — becoming the majority of organized labor for the first time, the Bureau of Labor Statistics reported Friday.

Private sector union membership plummeted by 10 percent last year, while government unions posted slight gains.

The shift shows the continued difficulty unions face in trying to revive a movement that has declined steadily since its peak of about 35 percent of workers in the 1950s. And it undermines the traditional ability of unions to push private sector wages higher.

Overall, union membership declined by 771,000 workers, to 15.3 million. That's 12.3 percent among all workers, dropping from 12.4 percent in 2008.

Government unions gained 64,000 members.

While public sector employment has largely held up in the recession, losses could hit government workers harder this year without more federal aid to states and localities.

The recession battered two industries with high union density — manufacturing and construction — leading to a decline in private sector union membership from 7.6 percent to 7.2 percent of all workers.

Companies have been more successful than governments in resisting union organizing drives.

"Employers can retaliate against private sector workers who want to form a union with impunity, and in the public sector it doesn't work that way," said Damon Silvers, policy director and special counsel at the AFL-CIO, the nation's largest labor federation.

Local government workers — a group that includes teachers, police officers and firefighters — had the highest union membership rate at 43.3 percent.

James Sherk, a labor policy analyst at the conservative Heritage Foundation, said the shift to public sector workers has increased labor's call for "higher taxes on Americans to fund more government spending."

Passing legislation in Congress that would make it easier for private sector workers to unionize has been a top priority of organized labor. But that's unlikely to pass this year, now that a Republican victory in a special election in Massachusetts has cost Senate Democrats and their independent allies their 60-seat majority.