President Barack Obama on Friday defended his pursuit of a sweeping trade pact as good for American workers in a global economy, dismissing fierce opposition from his own party as a “ratification of the status quo.”

The challenge for the Democratic president was on stark display hours before he began speaking at a White House news conference. Earlier in the day, Michigan Rep. Sander Levin, the senior Democrat of House Ways and Means Committee, declared he was “out to defeat” the legislation because, he said, it would cost U.S. jobs and damage the environment. Only a few Democrats in the House, Levin predicted, would support the legislation.

Obama said the authority he sought is the same exercised by past presidents of both parties. And the pact he’s seeking with 11 Pacific nations would prevent countries like China and Japan from having a leg up in global commerce.

“Being opposed to this new trade agreement is essentially a ratification of the status quo, where a lot of folks are selling here, but we’re not selling there,” Obama said.

He pointed to the various brands of Japanese-made cars filling the streets of Washington compared to the lack of GM, Chrysler and Ford vehicles in Tokyo.

“We cannot stop a global economy at our shores,” he said. “We’ve got to be in there and compete. And we’ve got to make sure we’re writing the rules so that we’ve got a level playing field.”

His comments came as many Democrats criticized the deal, announced Thursday, on the broadest bipartisan trade bill in years.

Under the agreement reached in Congress, Obama would get so-called trade promotion authority to negotiate trade pacts that Congress could approve or reject, but not change. Congress still has to vote on such fast-track authority, and many Democrats, including strong Obama allies, have vowed to fight it.

Senate Majority Leader Mitch McConnell said the challenge rests with Obama now.

“This is a time for presidential leadership,” he said, predicting most Republicans will vote for the bill. “Stand up, Mr. President. Make the arguments and deliver the Democratic votes we’ll need to get it passed.”

House and Senate committees plan to consider the measure next week, ahead of Japanese Prime Minister Shinzo Abe’s address to a joint meeting of Congress on April 29.

Obama faces opposition from key labor and environmental groups that form much of the liberal base of his party. He sought to reassure critics by saying deals with Asia and Europe would have enforceable labor and environmental protections and heed concerns about human rights.

“In many ways, this is the most far-reaching and progressive trade promotion authority that we have seen going through Congress’” Obama said. “It is entirely understandable that there is some skepticism around trade from working families who saw manufacturing collapse and jobs being outsourced.”

Levin dismissed the labor and environmental provisions as ineffectual. And other groups — the AFL-CIO, the Teamsters, the Sierra Club — stepped up their pressure on lawmakers to oppose the bill. Such agreements, they argue, wind up destroying jobs in the U.S. and creating jobs in nations that lack the environmental and worker safety protections that exist in the United States.