Vice President Biden says there is a “less than even” chance Congress ratifies the Trans-Pacific Partnership (TPP) trade agreement before the end of the Obama administration.

{mosads}Speaking at the Council of Foreign Relations on Wednesday in New York, Biden said “our only real shot” to approve the 12-nation trade pact is during the lame-duck session of Congress after the November elections.

“But it’s going to be hard,” he said, according to Reuters. “I think it’s less than an even chance, but there is a genuine chance. It’s possible we can get it passed.”

While Biden did not rule out the possibility of Congress approving the TPP, his comments are a candid admission that the politics surrounding the trade deal are shrinking the chances that it takes effect.

Both Democratic presidential nominee Hillary Clinton and Republican nominee Donald Trump oppose the deal, and congressional leaders have expressed doubt they will even hold a vote on it.

Senate Majority Leader Mitch McConnell (R-Ky.) has said the pact won’t get a vote in the upper chamber this year. Speaker Paul Ryan (R-Wis.) has said the TPP does not have enough support in the House to pass.

But Biden expressed optimism that lawmakers would reconsider their positions after Election Day.

“Sometimes when there’s no election to face and people are leaving and others who are staying, they may see the wisdom of TPP,” said Biden.

If Congress does not approve the TPP before President Obama leaves office in January, it would be a major blow to his second-term agenda.

The trade agreement has been one of the president’s top priorities during his last four months in office.

He argues it would boost the U.S. economy and play a role in repositioning the focus of the nation’s foreign policy toward the fast-developing Asia-Pacific region.

But critics say the deal would ship American jobs overseas. They also argue it has weak labor and environmental standards.