The heads of America’s best-known public broadcasters — PBS and National Public Radio — will appear on Capitol Hill Wednesday to answer charges from members of the House Department of Government Efficiency subcommittee that they are squandering taxpayer money on politically slanted programming.

The tone of the hearing can be clearly gleaned from the title chosen by the committee’s Republican managers: “Anti-American Airwaves: Holding the heads of NPR and PBS Accountable.”

The two broadcasters have long been in the crosshairs of conservatives who claim they are blatantly partisan and want to cut off taxpayer support. Wednesday’s meeting marks one of the first public hearings of the committee, inspired by Elon Musk’s drive to reduce government spending, with witnesses.  

The combative chairwoman of the committee, Marjorie Taylor Greene, is promising what she calls “must-watch” testimony from NPR’s chief executive, Katherine Maher, and PBS President Paula A. Kerger.

A video Ms. Greene posted on social media Tuesday to promote it is brimming with many of the catch-phrases conservatives have thrown around about the broadcaster — “Fake News,” “woke politics,” “Democratic propaganda,” as well as images of drag queen story hours and Mr. Trump being accidentally smacked in the face by an NPR microphone while speaking to reporters.

The video concludes with a slide saying the video was paid for by her Greene for Congress campaign.

Ms. Greene says taxpayers should not pay for “one-sided reporting, which attacks over half the country to protect and promote its own political interests.” In letters to both women, she said the hearing will be an opportunity to explain why federal funds should continue to be spent on public broadcasting.

NPR, in a statement in response to the letter, stated, “We constantly strive to hold ourselves to the highest standards of journalism.”

“We welcome the opportunity to discuss the critical role of public media in delivering impartial, fact-based news and reporting to the American public,” the statement added.

President Trump has complained about liberal bias in the press in general and has called for an end to taxpayer funding of public media. Earlier this month, he dismissed hundreds of employees of another public broadcaster, the Voice of America, but the move has been challenged in court.

In remarks at the White House Tuesday, Mr. Trump reiterated that he would not hesitate to cut off federal funding cut off for both PBS and NPR if given the chance. “I would love to do that,” he said. “I think it’s very unfair. It’s been very biased the whole group.”

“I look forward to working with the Trump administration to stop allowing the blatant misuse of taxpayer funds for partisan ends,” Ms. Greene says.

Public broadcasters say that federal funding is only a small portion of their revenue, which also comprises viewer donations solicited during pledge drives and revenue from corporate sponsors.

The nonprofit news organizations also face an FCC investigation into whether they are violating federal law by airing what the pro-Trump head of the Federal Communications Commission, Brendan Carr, calls “commercials” tied to those sponsorships.

In letters to the outlets, Mr. Carr said it is “possible that NPR and PBS member stations are broadcasting underwriting announcements that cross the line into prohibited commercial advertisements.”