President Barack Obama is riling his base of supporters again, this time over his push for action on a free trade agreement with South Korea — a deal that has stalled for years amid a Democratic outcry over the potential effect on manufacturing jobs in their districts.

Obama announced at the Group of 20 summit last month that he wants to wrap up negotiations on the deal by November, when he is scheduled to visit South Korea. He then plans to send the agreement to Congress for an up-or-down vote on its ratification.

“We are going to do it in a methodical fashion,” he said last week. “I want to make sure that everything is lined up properly by the time that I visit [South Korea] in November. And then in the few months that follow that, I intend to present it to Congress.

“It is the right thing to do for our country. It is the right thing to do for” South Korea, Obama added.

The sudden timeline for wrapping up the agreement set off a firestorm among Democrats in manufacturing-heavy states, who say the president first needs to endorse legislation that ensures equal market opportunities for American workers.

For Democratic trade critics, Obama’s free trade push runs contrary to his talk during the Democratic primaries of getting tough on trade agreements and adds to already sky-high anxieties over jobs in their districts.

“We need a change in trade policy, not more of the same,” said Sen. Sherrod Brown (D-Ohio). He said the current South Korea deal is similar to past trade agreements “that have undermined Ohio workers and manufacturers.”

“Until we vigorously enforce trade laws, including the use of remedies to crack down on currency manipulation, it makes little sense to take up this agreement,” Brown added.

House Rules Chairwoman Louise Slaughter (D-N.Y.), a member of the House Trade Working Group, called it “backward” to move the agreement at a time when many Americans are looking for work. She said the president may vow to work together with lawmakers to find common ground on the deal, but it will require “significant changes” to gain broad Congressional support.

“I am surprised that the administration would try to slide this poorly written trade deal past the American public when Congress has already said that the deal is not good for our economy or workers,” she said.

Rep. Phil Hare (D-Ill.), who also is in the House Trade Working Group, said he is disappointed that Obama “would even consider” taking up the South Korea deal at a time when the economy is on its way up.

“Without fail, every administration in my adult life, regardless of party, has pushed unfair trade,” Hare said. “America’s auto industry and work force are finally back on their feet. This trade agreement, even if it is retooled, would knock them down again.”

Carol Guthrie, a spokeswoman for the Office of the U.S. Trade Representative, said that trade officials are “very aware” that some Members are unhappy with the current agreement and that her office is prepared to work out their differences in the coming months.

“We will certainly be meeting with those who are expressing concerns and wish to talk about this,” she said.

Guthrie said Obama’s push on the issue should not come as a surprise, because it is “extremely consistent” with what he said about trade agreements in his State of the Union address in January. In his speech, he specifically cited the South Korea deal and warned that, without action, America will end up sitting on the sidelines while other nations sign agreements.

The South Korea pact has the potential to add $12 billion to the annual gross domestic product and create as many as 70,000 jobs, Guthrie said. “If we’re going to move forward on this promise to grow jobs by increasing our exports, this is a prime opportunity to do it,” she added.

The United States has been slipping in its standing as a trade partner with South Korea. In 2003, the United States was South Korea’s largest trading partner. Now the United States ranks fourth, and other countries are lining up for their market share of South Korea. Both the European Union and Australia are on track to wrap up their deals this year, with China kicking off negotiations next year.

Guthrie said her office has been talking to key lawmakers on the issue for the last year and that Obama’s latest push will kick off “an intensified consultation process with Congress” in the coming months.

House Democratic leaders are likely to wait to see the administration’s final product before weighing in on the timing of a vote.

“Many Members of Congress continue to have concerns about aspects of the South Korea free trade agreement,” said Nadeam Elshami, a spokesman for Speaker Nancy Pelosi (D-Calif.). “The Obama administration has stated that it will consult closely with Congress during the negotiations and will work to resolve those concerns before an agreement is sent to Congress.”

House Ways and Means Chairman Sander Levin (D-Mich.), the House’s point man on trade, also said the agreement will have to be significantly reworked to pass muster.

Not all Democrats are opposed to the president’s overtures on trade. Leaders of the pro-business New Democrat Coalition welcomed the news of Obama restarting talks on the deal.

Other lawmakers have launched a bipartisan working group focused on advancing the South Korea trade deal. Members include Reps. Bobby Bright (D-Ala.), Dave Reichert (R-Wash.), Peter Roskam (R-Ill.), Diane Watson (D-Calif.), Erik Paulsen (R-Minn.) and Adam Smith (D-Wash.).

“South Korea has proved to be one of our closest friends and allies, and it’s well past time for Congress to pass the U.S.-South Korea free trade agreement,” Bright said.

Steven T. Dennis contributed to this report.