Washington, D.C. ? Union membership jumped to 12.4 percent of the nation’s work force last year, amid widespread job losses and credit woes.

The ranks of organized labor rose by 428,000 workers in 2008, the biggest annual gain since the government began compiling such data in 1983, the Bureau of Labor Statistics reported Wednesday.

It’s also the second year in a row that unions have added to their ranks. Membership grew by 311,000 in 2007, to account for 12.1 percent of workers.