Chuck Schumer is gearing up for a showdown with Trump over his voter-fraud commission

Senate Minority Leader Chuck Schumer signaled a possible fight over President Donald Trump's election integrity commission on Thursday when he called for Congress to "prohibit its operation" as a part of "must-pass" September legislation.

In a Medium post titled "After Charlottesville, It's Time to End the Assault on Voting Rights," Schumer called on Trump to rescind the executive order creating the panel to investigate voter fraud and other electoral integrity-related issues.

"If the president wants to truly show that he rejects the discrimination agenda of the white supremacist movement, he will rescind the executive order that created this commission," Schumer said. "And if the president does not act, the Congress should prohibit its operation through one of the must-pass legislative vehicles in September."

"Many of us found the Election Integrity Commission distasteful when it was first created," he continued. "The president's recent failure to unequivocally condemn bigotry makes its rescission imperative."

Schumer additionally called for public hearings on voting rights, which he said should include testimony from Kansas Secretary of State Kris Kobach, the vice chairman of Trump's commission.

Several must-pass bills are on the table for Congress in September, including legislation to raise the debt ceiling and fund the government. Trump threatened a shutdown at his Tuesday rally in Arizona, and signaled a possible debt ceiling battle in a pair of Thursday morning tweets.

In an email exchange with Business Insider, Matt House, Schumer's communications director, said Schumer could also look to other must-pass legislative vehicles, including extending the Children's Health Insurance Program and reauthorizing the National Flood Insurance Program.

"He's not picking a specific one," House said.

The voter fraud panel, which was created in the aftermath of Trump's baseless claim that millions of people voted illegally in last year's presidential election, held its first meeting last month. Some fear the true purpose of the commission is to suppress votes from certain minority groups that typically vote Democratic.