Women are on track to become a majority of unionized workers in the next 10 years, signaling their growing clout in the labor movement.

The shift, outlined in a report Tuesday from the Center for Economic and Policy Research, could see organized labor focus more intensely on issues important to women as unions look to broaden their ranks and wield greater political strength in the next election cycle.

"When you have a majority of women in the labor movement, issues like work-family balance, paid sick days and paid parental leave become more important," said John Schmitt, an economist at the left-leaning think tank and one of the authors of the report.

The study tracks the growing diversity of the labor movement over the past quarter century, including a surge in Latino union members and the steep decline of unionized workers from the manufacturing sector.

Women now make up about 45 percent of union members, up from just 35 percent in 1983. That number is expected to move past 50 percent by 2020. White men now make up 38 percent of the union work force, down from 51.7 percent in 1983.

Latinos are the fastest-growing ethnic group in organized labor, more than doubling their representation from 5.8 percent to 12.2 percent over the past 25 years. Asian workers also saw their union ranks swell from 2.5 percent in 1989 to 4.6 percent in 2008.

Anna Burger, head of the union federation Change to Win, said women have changed the tenor of politics in the labor movement.

"Because of women, we don't just talk about raising wages, but about creating family friendly workplaces with sick leave, child care, and family and medical leave," Burger said. "We don't just talk about out-of-control insurance costs, but about the fact that women pay more than men strictly because of their gender."

After years of steady declines, union ranks have grown slightly over the past two years. Union members now represent 12.4 percent of the nation's work force, down from about 20 percent in 1983.

Much of the growth has come from the public sector, where women make up a greater percentage of employees than in private industry. About 49 percent of all unionized workers are government employees and 61 percent of unionized women come from the public sector.

Liz Shuler, the new secretary-treasurer of the AFL-CIO, said the numbers reflect an active push for diversity. It could translate into more political clout as well, as union voters make up 20 percent to 25 percent of the electorate.

"When we increase our representation with women and minorities, we know that's the fastest-growing segment of new voters as well," Shuler said.