The Teamsters International, which represents more than 1.3 million workers, declined to endorse a candidate ahead of November’s presidential election – but released data suggesting that most of its members support Donald Trump over Kamala Harris.

The union’s decision not to endorse for the first time in nearly three decades came amid criticism of its president, Sean O’Brien, who was the first Teamsters leader to speak at the Republican convention in July. Teamsters vice president John Palmer called the decision to appear at the convention “unconscionable” given Trump’s past anti-union stance.

Harris, the Democratic presidential candidate, met with the Teamsters this week for a round of talks ahead of the decision. Trump and Joe Biden attended a round of talks with the union earlier this year.

“Unfortunately, neither major candidate has been able to make serious commitments to our union to ensure that the interests of working people always come before the interests of big business,” O’Brien said in a statement Wednesday. “We have demanded commitments from both Trump and Harris not to interfere in key union campaigns or core Teamsters industries – and to respect our members’ right to strike – but we have been unable to achieve those commitments.”

Polling data released by the union before the announcement showed that its members supported Biden over Trump. However, more recent polls conducted by the union found that members supported Trump over Harris.

The Teamsters National Black Caucus endorsed Harris last month.

In response to the rejection, Teamsters against Trump, a grassroots group of Teamsters members and retirees, announced that it would step up its campaign efforts to elect Vice President Kamala Harris.

The California Teamsters also endorsed Harris on September 18 in response to the lack of support from Teamsters International.

“When it comes to my vote for president, as a proud Teamster, there is no contest. Donald Trump doesn’t give a damn about the working class. As president, Trump didn’t lift a finger to help the Teamsters whose pensions were in jeopardy. Instead, he put his billionaire friends in the White House and did everything he could to keep workers from organizing into unions,” James Larkin, a member of Teamsters Local 299 in Detroit, Michigan and a member of the group, said in a statement.