President Bush said Monday that Americans will lose jobs and economic growth if Congress insists on the right to make "eleventh-hour changes" to a free-trade agreement with Mexico and other trade pacts.

Bush, keeping up the drumbeat for extension of his fast-track trade authority, dismissed big labor, environmentalists and other critics of the trade accord with Mexico as "fear-mongers.""They seem to be the only ones who haven't learned lately that defeatism produces defeat, while confidence and self-reliance produce greatness," Bush said in a breakfast speech before 150 Hispanic business leaders.

Bush praised "those Democrat leaders in the U.S. Congress . . . who have the vision" to support the pact, including House Speaker Tom Foley and Sen. Lloyd Bentsen of Texas. Critics include House Majority Leader Richard Gephardt.

"I'm going to approach this strictly in a non-partisan, non-political manner. It is too important to get it bogged down in partisan politics," said Bush.

Bush made his pitch the day after vowing with Mexican President Carlos Salinas de Gortari to fight hard for the agreement, and resolving to go "head-on-head" against the AFL-CIO, which fears an erosion of jobs to south of the border.

He also praised Salinas on Monday, saying, "He's doing a first-class job. He's moved that country in ways that some of his critics would have never dared dream possible."

Bush was flying later Monday to Dallas to attend a memorial for John Tower, the former senator killed in a plane crash last Friday, and to throw out the first ball at the Texas Rangers' first game of the baseball season Monday night.

Bush's fast-track negotiating authority allows for only up or down votes in Congress on trade pacts. It expires May 31, but will automatically be renewed for two years unless a simple majority of either the House or Senate objects.

Bush said his ability to secure a global trading agreement in the Uruguay Round and a South American trade initiative as well as the trilateral accord with Mexico and Canada are at stake.

"Fast-track doesn't affect Congress' power to accept or reject trade agreements. But it does prevent eleventh-hour changes to agreements we have reached . . . that force everyone involved to start from scratch," said Bush.

"If we lose our fast-track authority, we lose any hope of achieving these three agreements. We lose trade. We lose jobs and jeopardize economic growth," said Bush.

He dismissed charges that the pact would harm the environment by hastening largely unregulated industrial growth in Mexico. He said Salinas "has shown he's serious about cleaning up the environment. . . ."

He said wages in Mexico, now one-tenth the going rate in the United States, will rise. "Someone ought to ask the opponents of fast-track why they oppose prosperity in Mexico," he said.