WASHINGTON — The House Oversight Committee has invited the new postmaster general to appear at a hearing next month to examine operational changes to the U.S. Postal Service that are causing delays in mail deliveries across the country.

The plan imposed by Louis DeJoy, a Republican fundraiser who took over the top job at the Postal Service in June, eliminates overtime for hundreds of thousands of postal workers and orders that mail be kept until the next day if postal distribution centers are running late.

Rep. Carolyn Maloney, a New York Democrat who chairs the Oversight panel, said the Sept. 17 hearing will focus on “the need for on-time mail delivery during the ongoing pandemic and upcoming election,” which is expected to include a major expansion of mail-in ballots.

President Donald Trump has warned that allowing more people to vote by mail will result in a “CORRUPT ELECTION” that will “LEAD TO THE END OF OUR GREAT REPUBLICAN PARTY,” even though there’s no evidence that will happen. Trump, Vice President Mike Pence and other top administration officials frequently vote absentee themselves.

Last week, Trump even floated on Twitter the prospect of delaying the Nov. 3 election — an idea lawmakers from both parties quickly shot down.

Trump has called the Postal Service “a joke” and said package shipping rates should be at least four times higher for heavy users like Amazon. But shipping and packages are actually a top revenue generator for the Postal Service, and critics say Trump is merely looking to punish Amazon founder and CEO Jeff Bezos in retaliation for unflattering coverage in The Washington Post, which Bezos owns.

The hearing comes as the Postal Service is reeling from mail delays and financial problems, even as record numbers of mail ballots are expected in the presidential elections because of the coronavirus pandemic.

Postal Service officials, bracing for steep losses from the nationwide shutdown caused by the virus, have warned they will run out of money by the end of September without help from Congress. The service reported a $4.5 billion loss for the quarter ending in March, before the full effects of the shutdown sank in, and expects losses totaling more than $22 billion over the next 18 months.

Bills approved by the Democratic-controlled House would set aside $25 billion to keep the mail flowing, but they remain stalled in the Republican-controlled Senate

Democratic lawmakers have demanded answers from DeJoy following complaints from constituents about mail service delays and other problems.

“It is essential that the Postal Service not slow down mail or in any way compromise service for veterans, small businesses, rural communities, seniors and millions of Americans who rely on the mail — including significant numbers who will be relying on the Postal Service to exercise their right to vote,” a group of Democratic senators wrote in a letter to DeJoy last week.