U.S. Trade Representative Robert Lighthizer has sent the House of Representatives the latest White House proposal for addressing Democrats concerns in the U.S.-Mexico-Canada Agreement.

Democrats are now reviewing the proposal, according to Reuters.

House leadership holds the key to passing the agreement that replaces the North American Free Trade Agreement.

Democrats have argued for stronger labor, environmental and enforcement standards within the trade agreement.

While little details have emerged as to how the White House proposes to address those concerns, optimism is growing that Congress can pass the agreement before the end of the year.

Ag organization leaders and farm-state lawmakers attended a rally outside the Capitol Thursday morning, in support of USMCA.

American Farm Bureau Federation President Zippy Duvall says passing the agreement would “bring certainty to our already-positive trade relationship with our closest neighbors.”

The rally included House Ag Chairman Collin Peterson and the committee’s top Republican Mike Conaway.

Lighthizer is expected to meet with the House working group on USMCA next week.