A U.S. Postal Service official has alleged that the agency is moving forward with a “secretive, rushed” effort to implement President Trump’s order exerting federal control over mail voting, despite a court order blocking those plans.

The official filed a whistle-blower report, published on Tuesday morning by the office of Senator Richard Blumenthal, Democrat of Connecticut, asserting that the “risky and haphazard” implementation of Mr. Trump’s order could lead to a “catastrophic failure” in the mail ballot system ahead of this year’s midterm elections. The report said that the agency had planned to complete the new digital system overseeing mail ballots by Sept. 1.

“Potentially millions of American voters may not receive their mail-in ballot this election cycle in a timely manner, or at all,” the official said in the report, which was prepared with the assistance of Whistleblower Aid, a nonprofit group that represents people seeking to expose potential lawbreaking.

Speaking to reporters by phone on Monday, Mr. Blumenthal said of the report that “the main takeaway for me is that the Postal Service has designed a system to disenfranchise millions of Americans. One-third of all Americans cast their ballots by mail, and the U.S.P.S. puts all of their votes at risk.”

The whistle-blower report provided specific details of the Postal Service’s effort to rapidly implement a new digital system for mail ballots, even as a federal appeals court had blocked the plan before the Supreme Court intervened. Work has also continued on the system even after Judge Talwani ordered the plan halted last week, the report said.

The official at the Postal Service raised “grave concerns” in the report that the verification process in the system could reject tens of thousands of ballots in a bulk-mailing batch if “even one bar code on one single ballot” failed to properly scan, and that the rushed, “slapdash” development of the system would significantly increase the chance of errors and other failures in the verification process.

The Brazilian billionaire who shares control of JBS, the world’s largest meatpacker, lobbied President Trump to lower tariffs on beef imports as a way to tame rising U.S. prices.

Joesley Batista met with Trump in the Oval Office on Aug. 20, and they discussed how additional beef supplied from Brazil could help if Trump dropped a 26% import tax, according to people familiar with the matter. It couldn’t be learned who organized the meeting between Batista and Trump.

The next day, on social media, Trump announced a plan to temporarily allow more foreign beef imports into the U.S. Trump said the imported products would be sold at a 25% discount to market prices.