SPRINGFIELD — It's been almost 10 months since protesters opposed to the Trans-Pacific Partnership, or TPP, rallied outside Congressman Richard Neal's Springfield office to voice concerns about the free trade deal that's been under negotiation for about a decade.

Demonstrators are again expected to descend on the Democratic congressman's office next week, when they'll ask him to publicly declare opposition to any fast-track legislation for TPP. Such legislation would implement the free trade pact with minimal debate and no amendments, with the entire process taking no more than three months before the agreement is up and running.

To date, Neal is the only member of Massachusetts' delegation to the House of Representatives who hasn't publicly stated his position on fast track, as the issue is known in political shorthand. That's why protesters plan to press him on the matter when they gather outside his State Street office on Feb. 18, from noon until 1 p.m. At the same time, protesters are slated to gather outside Neal's Pittsfield office at 78 Center St.

William Tranghese, Neal's press secretary, didn't immediately respond to an email message for comment about the upcoming rallies.

TPP is essentially a massive free trade deal between the U.S. and Canada and 10 nations in the developing Asia-Pacific region that would account for 40 percent of the world's economic activity, serving as a potential antidote to China's economic inroads into the region.

President Obama, who views the deal as the linchpin of his administration's economic policy in that part of the world, and other advocates say TPP would boost U.S. economic growth, support American jobs, and gain market access for Made-in-America exports to some of the fastest-growing nations in the world. The agreement also would establish trade rules, including rigorous regulation of labor and environmental standards of participating nations.

Congress, over the past couple of decades, has ceded more authority to the president to broker trade agreements, specifically the right to engage in "trade promotion authority" – an approach more commonly called "fast track." This authority essentially strips lawmakers of the ability to debate details of a trade agreement before a final up-or-down vote is taken.

"You're asking members to give away their leverage on a historic trade agreement when there are major issues outstanding," Congressman Sander M. Levin, Neal's colleague on the Ways and Means Committee, told The New York Times in December. Levin said a vote on fast-track authority before the presentation of a completed TPP deal "would be a donnybrook," the Times reported.

Because TPP talks have largely been conducted in secret – that's standard operating procedure for most trade negotiations – trade unions, environmentalists, global health advocates and other critics are concerned about what unknown details might be lurking in the pact.

Leaders of Western Mass. Jobs With Justice, one of the groups organizing the protests outside Neal's Western Massachusetts offices, posted a statement on Facebook that reads: "We are asking U.S. Rep. Richard Neal to stand up against Fast Track – an undemocratic, 1970s-era procedure that has been used to railroad the most controversial and damaging of U.S. 'trade' deals through Congress."

TPP is one of the greatest threats to American jobs, a living wage, clean air and water, and "democracy as we know it," according to the protest organizers. If Neal comes out publicly against trade promotion authority for TPP, "this rally will be a Thank You" to the congressman, organizers said.

Other protest sponsors include local AFL-CIO labor councils, Progressive Democrats of America, MoveOn.org, Berkshire Environmental Action Team, Public Citizen's Global Trade Watch, and Communications Workers of America.

At last year's demonstration, held outside Neal's Springfield office in late April, fellow Democrats said they wanted the dean of the state's U.S. congressional delegation to know that fast track is bad news for American workers.

"Too often we are told that these trade agreements are good for jobs, good for the economy, and for the people, but those promises rarely are true," Bill Shein, a Berkshire County resident and one-time challenger to Neal's congressional seat, said at the 2014 rally.

"It is good for corporate profits and the politicians who they write checks to – not the average working people. The benefits just don't flow down to the working class," he said.