The International Association of Machinists and Aerospace Workers is calling on Sen. Chuck Schumer to make way for new leadership, adding a prominent labor voice to the debate over who should guide Senate Democrats after last week’s elections.

In a letter sent Monday, the 600,000-member union urged the New York senator not to seek another term as Democratic leader. IAM International President Brian Bryant said the appeal followed discussions with the union’s executive council.

“Working people are demanding change,” Bryant wrote, arguing that the moment calls for “fresh ideas, new energy and a new generation of leadership.” The letter was copied to the full Senate Democratic Caucus and obtained by POLITICO.

Bryant offered a sharper assessment in a statement to POLITICO, saying the union was through with political leaders who fall short of being a “ferocious, unyielding and unbending champion of working people.”

Schumer’s office declined to comment. A Senate Democratic aide, granted anonymity to speak candidly, called the letter counterproductive and described Schumer as a longtime IAM ally and steadfast champion of labor.

Bryant acknowledged that relationship in his letter, thanking Schumer for a decade leading Senate Democrats and calling him “a trusted friend of organized labor.” He urged returning and newly elected Democratic senators to choose a consensus leader through a fair and open process.

The union also outlined priorities for the next leader, including passage of a rail safety bill and the PRO Act, which would make it easier for workers to unionize. It called for restoring bargaining rights for federal workers and reviving enhanced Affordable Care Act subsidies that Republicans allowed to expire.

The Senate Democratic aide said the union’s opposition was particularly puzzling given Schumer’s longstanding commitment to the PRO Act.

The letter arrived on the eve of the first full Senate Democratic Caucus meeting since the midterm elections, when lawmakers are expected to begin charting a path toward selecting their next majority leader. Some Democrats are weighing a leadership change as the party looks ahead to 2028.

Sen. Chris Van Hollen of Maryland said Monday night that he was still considering a challenge to Schumer. Sen. Elissa Slotkin of Michigan has said she wants to hear Schumer’s vision for the next two years before committing her support.