(In paragraph nine, corrects Debbie Dingell's title to representative from senator)
By Lesley Wroughton
WASHINGTON, July 17 (Reuters) - U.S. labor union leaders and Democratic lawmakers on Monday reminded U.S. President Donald Trump they expect him to keep election campaign promises to protect American workers in NAFTA talks, but they stopped short of demanding termination of the 1994 trade pact with Canada and Mexico.
Their comments came hours before U.S. Trade Representative Robert Lighthizer was to outline the administration's priorities for the talks. Under U.S. "fast-track" rules, the administration must release the priorities 30 days before negotiations begin.
President Richard Trumka of the AFL-CIO, an umbrella organization of unions representing 12.5 million workers, said the North American Free Trade Agreement had been an "unequivocal failure" and should be completely renegotiated.
"We will do everything we can to make this a good agreement and to hold the president at this word and make sure we get a renegotiation," he told a conference call with reporters.
"If it comes out that it is not a good deal, no deal is better than a bad deal," said Trumka.
The document outlining White House priorities was expected on Monday afternoon, said House Democrat Rosa DeLauro of Connecticut, a leading voice against trade legislation on Capitol Hill.
The Trump administration has so far offered few specifics, other than expressing its desire to modernize the pact to increase U.S. manufacturing jobs and cut the trade deficit.
Some provisions from the Trans-Pacific Partnership, which Trump abandoned, are likely to serve as a model for NAFTA revisions, especially on issues such as labor, environment, intellectual property rights and state-owned enterprise.
Democratic Representative Debbie Dingell from Michigan. which is home to large automakers like Ford, General Motors and Fiat Chrysler, said she offered to work with the administration if it was serious about the talks.
Dingell in the past has called for U.S. trade deals to contain explicit provisions to deter currency manipulation by trading partners.
NAFTA has quadrupled trade among the three countries, surpassing $1 trillion in 2015. Over a decade to 2010, however, the United States lost nearly 6 million manufacturing jobs. The U.S. trade balance with Mexico also swung from a small surplus in 1994 to deficits that have exceeded $60 billion for most of the past decade.
Bob Martinez, who heads the International Association of Machinists and Aerospace Workers, said labor unions should be present at the NAFTA negotiating table.
"I am requesting such," said Martinez. "Any renegotiation that starts off with the current trade template found in TPP is unacceptable," he said.
Reporting by Lesley Wroughton and David Lawder; Editing by Cynthia Osterman