Leaders of two key congressional panels have agreed on a deal that would “fast-track” the Obama administration’s ability to draft a pair of controversial international trade bills and move them through Congress.

If passed, the agreement, known as the “trade promotion authority” bill (TPA), would permit President Barack Obama to expedite the process of authorizing trade deals such as the Trans-Pacific Partnership (TPP) – currently being drafted by the US and 11 other Pacific nations – and the Transatlantic Trade and Investment Partnership (TTIP) with the European Union.

Under the rules of the TPA, Congress would be able to vote on whether or not to approve either of the deals, but they would not be allowed to offer any amendments that could potentially alter the substance of the agreements.

TPP agreement will be public for 4 months before Congress votes. http://t.co/eWF6mRtVxV — Nancy LeTourneau (@Smartypants60) April 16, 2015

Additionally, the TPA would set guidelines for US negotiators currently hammering out details with their international counterparts. For example, it requires that American negotiators work out an understanding on human rights with trade partners, the New York Times reported, which has never been required for international deals before.

It would also require that any final trade agreement be made public about two months before the president signs it into law and up to four months before it comes up for a vote in Congress.

Of the two deals, the TPP has garnered the most press due to the White House’s stated “pivot” to Asia, which involves rebalancing American focus to East and South Asia. However, most of the pact’s details remain secret – itself a cause for concern among skeptics. Supporters of the TPP argue that it will open up markets and opportunities for American goods as well as boost America’s profile in Asia, where a rising China poses multiple challenges.

READ MORE: Leaked TPP investment chapter: Corporations can sue states in private courts

President Obama said he was “pleased” with the deal in a statement. He acknowledged that past trade deals “haven’t always lived up to their promise,” but pledged to sign a deal that would benefit ordinary Americans. He also said deals like the TPP are important avenues through which America could maintain its influence on the global economy.

“The bill put forward today would help us write those rules in a way that avoids the mistakes from our past, seizes opportunities for our future, and stays true to our values,” Obama said. “It would level the playing field, give our workers a fair shot, and for the first time, include strong fully enforceable protections for workers’ rights, the environment, and a free and open internet.”

Opponents, however, are worried about a plethora of issues, including the possibility that the TPP would cost Americans jobs and only benefit corporations as well as the already wealthy. There are also concerns that the agreement won’t do enough to establish labor and human rights in countries like Vietnam, that it would make the internet less free around the world, and that environmental protections won’t be strong enough.

READ MORE: Democrats to fight Obama on secret trade deal authorization

On top of these fears, some lawmakers, such as Sen. Sander Levin (D-Mich.), question the extent to which new markets will actually embrace the US. Japan, for example, has resisted eliminating tariffs on American agricultural products and opening its market to the automotive industry, although there have been reports that Tokyo will reduce tariffs on a few hundred products.

Levin called the TPA “a major step back,” while Sen. Chuck Schumer (D-N.Y.), widely expected to take the reins of the Democratic Party in the Senate once Minority Leader Harry Reid (D-Nev.) leaves office, criticized the quick process by which the terms of the TPA were struck.

“This process is not good,” he told the Huffington Post.“We are supposed to vote on TPA, tie our hands and not vote on amendments, before we’ve seen what the [Trans-Pacific Partnership] is. I’ve never seen anything like it.”

Labor unions, environmental and internet advocacy groups have loudly protested the TPP, but Sen. Ron Wyden (D-Ore.) a key lawmaker needed to ensure passage of any expedited deal, tried to assuage fears by saying the bill allows Congress to revoke fast-track authority if the White House fails to meet the criteria it sets out. However, it’s unlikely that such provisions will mollify opponents.

It’s also unlikely that Obama will secure approval from the majority of his party even if and when the TPP is finalized, as many Democrats have come out against it. Republicans have generally voted in favor of such deals, though – and they control both chambers of Congress – so expectations are that a deal could pass in a rare show of bipartisan cooperation.

The TPP is being negotiated among the US, Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.