WASHINGTON - President-elect Barack Obama's choice to be labor secretary, Democratic Rep. Hilda Solis of California, is expected to advocate greater union influence in the workplace and more "green" jobs.

Solis, 51, the daughter of a Mexican union shop steward and a Nicaraguan assembly-line worker, is in line to be the second Hispanic nominee in Obama's Cabinet. Obama planned to announce her nomination today, said a Department of Labor official who spoke on condition of anonymity.

The lone member of Congress of Central American descent, Solis would replace Elaine Chao, the only original member of President George W. Bush's Cabinet still in office.

Unions, which contributed heavily to Obama and Democrats this year, expect Solis to be an advocate for them and for workers. They expect her to press for legislation that would force businesses to recognize union representation once more than 50 percent of a company's eligible workforce signs union cards, instead of waiting for secret-ballot elections.

Unions claim that managers coerce and intimidate workers into rejecting unions in secret ballots at work. Employers say that workers often are coerced themselves by their peers to sign union cards and that a secret-ballot election is the only way to determine their true wishes.

"Unions are vital to the health and strength of our communities, and our workers are the bedrock of our economy," Solis said in 2007, while advocating for the Employee Free Choice Act. "In this day and age when the number of women and new immigrants is increasing in the workforce, it is important that they become a part of the American fabric and one of the ways is to be a member of a union."

"We're confident that she will return to the Labor Department one of its core missions - to defend workers' basic rights in our nation's workplaces," said John Sweeney, president of the AFL-CIO, the nation's largest labor organization. *