Democratic presidential candidate John Edwards is getting the endorsement of two unions, the United Steelworkers and the United Mine Workers of America, on Labor Day.

Edwards is scheduled to be in Pittsburgh, home of the Steelworkers' international headquarters, for a Monday rally and will accept the endorsements there.

"The members of the Steelworkers Union and the Mine Workers union are some of the country's hardest-working, bravest, most courageous workers," Edwards said. "It is their tireless hard work which has helped build a stronger America that benefits all of us. I honor what they do every day."

The former senator from North Carolina, who has worked hard to get labor endorsements, has also secured the backing of the United Brotherhood of Carpenters and Joiners of America.

The steelworker and mine worker endorsements mean that Edwards now has more labor endorsements than any of the other Democratic presidential candidates.

New York Sen. Hillary Rodham Clinton has been endorsed by the United Transportation Union and the International Association of Machinists and Aerospace Workers. Connecticut Sen. Chris Dodd has been endorsed by the International Association of Fire Fighters.

Edwards suggested Clinton's campaign represents politics-as-usual in Washington and that Edwards represents a break from the past.

"We just have a disagreement," Edwards said on ABC's "Good Morning America." "Sen. Clinton defends Washington lobbyists and the system that exists in Washington and thinks she can work within that system. If that were true we would already have universal health care. If that were true America would already be attacking global warming in a serious way."

The United Steelworkers is the largest industrial union in North America, with 850,000 members and retirees in the metals, mining, rubber, paper, oil refining, chemicals and service industries.

The mine workers union has been in the news recently, advocating for increased safety for coal miners. The union, which includes coal miners, clean coal technicians, health care workers, truck drivers and school board employees, claimed more than 86,000 members on its 2006 Labor Department disclosure forms.

The Steelworkers endorsed former Missouri Rep. Richard Gephardt in the 2004 primaries until he dropped out, and then threw their support behind the failed presidential candidacy of Democratic Sen. John Kerry, D-Mass.

The Steelworkers gave $2.4 million, all to Democrats, in the 2006 House and Senate races in which the GOP lost control of Congress. In the last presidential cycle, the Steelworkers gave almost $1.2 million to federal candidates, with 99 percent of the 2004 money going to Democrats.

In 2004, the mine workers union gave $510,100 to federal candidates, with 93 percent of it going to Democrats. The United Mine Workers gave $496,050 in the 2006 elections, with 97 percent of it going to Democrats.