During a campaign season in which President Trump has been criticized for using federal resources for his political benefit, House Republicans on Wednesday said they are leading an inquiry into Joe Biden’s use of an Amtrak train to campaign last month.

Four GOP members, in a letter to the government-subsidized railroad, alleged that the Biden campaign may have received “special treatment” and had refused to say how much it paid to charter an Amtrak train through Ohio and Pennsylvania last month.

“We are concerned that the apparent use of a struggling, resource-deprived, publicly-run service for political gain does not serve the best interests of Amtrak or the American taxpayers at this time,” wrote Reps. Eric A. “Rick” Crawford (R-Ark.), Bob Gibbs (R-Ohio), Scott Perry (R-Pa.) and Lloyd Smucker (R-Pa.).

But in its disclosures to the Federal Election Commission, the Biden campaign reported spending $265,000 on the train charter. Amtrak says that the starting rate for a charter is $30,000, and that no discount was given. “We can’t provide the cost, but can share that we did make money, as we aim to do for any charter,” Amtrak said in a statement.

A Biden campaign spokesman dismissed the allegations, saying that “anyone can charter a train with Amtrak.”

“Last time we checked, no one can charter the White House South Lawn for a political convention,” spokesman Matt Hill said in a statement. “Instead of wasting time on political stunts, congressional Republicans should stop ignoring Donald Trump’s blatant abuses of taxpayer money and government resources to enrich himself and his businesses.”

Donald K. Sherman, a former government ethics and oversight official and deputy director of Citizens for Responsibility and Ethics in Washington, said the Trump administration has repeatedly tapped government resources to advance the president’s campaign, in violation of federal law.

He cited a White House rally Oct. 10 that was billed as an official event; comments made by adviser Peter Navarro on Fox News seeking to undercut Biden; and Agriculture Secretary Sonny Perdue’s public statements pushing for Trump’s reelection at an event discussing the Farmers to Families Food Box program.

Sherman said the concerns raised by the House members aresomewhat laughable in the face of blatant abuse by the Trump administration of the enormous resources at its disposal. …”

“It’s hard to compare them, in part because Joe Biden doesn’t work for the government. It’s like apples and bicycles,” Sherman added. “This administration has bent and broken the rules limiting the administration’s use of official government resources and authority for campaigning on a near-daily basis leading up to the election.”

The White House, according to spokesman Judd Deere, “takes the Hatch Act very seriously and ensures its events, and the government employees participating in them, comply with the law,” referring to prohibitions on partisan political activity by federal workers.

The House members said that “we want to ensure that the campaign paid a full, non-discounted rate” for the train, and they questioned “whether the Biden campaign’s use of Amtrak caused delays of freight trains at a time when supplies are crucial” during the pandemic.

“This was a multi-stop charter train along the freight rail network, so that type of complex schedule — compared to a more straightforward ‘point A to point B’ train — adds to the questions and concerns about its potential impacts,” said Justin Harclerode, a spokesman for Republicans on the House Committee on Transportation and Infrastructure.

Amtrak said that “no discounts or scheduling preference” was given to Biden and that “the railroad industry has a long history of operating special trains for public officials on both sides of the aisle and Amtrak has been part of that.”

“Operation of charter trains is an important revenue source for Amtrak and one that supports other parts of our business," the railroad said in a statement. “Customers range from sports teams to businesses, historical groups and even individuals whose private railcars are coupled to our trains,” Amtrak said.

The company said pricing for charters is based on the customer’s operational needs and additional services.

“In this instance, the rate aligns with our standard practice and market rates that anyone seeking this service would be charged. There were no discounts or scheduling preferences,” the company said.

An Amtrak historical article recounts the long history of presidential campaigns taking to the rails. William Henry Harrison was the first presidential candidate to do so, in 1836, according to historians. In modern history, Jimmy Carter (D), Gerald Ford (R) and George H.W. Bush (R) took trains on campaign tours. Harry S. Truman (D), during his 1948 “whistle-stop” tour, traveled more than 28,000 miles and delivered more than 350 speeches.

In 1996, President Bill Clinton (D) used Amtrak for a campaign trip that made stops in West Virginia, Kentucky, Ohio, Michigan and Indiana, and four years later, George W. Bush (R) took his campaign to California’s Central Coast, on a tour aboard Amtrak’s Coast Starlight and Pacific Surfliner.

In recent years, Republicans have led efforts to defund Amtrak, which receives about $2 billion in federal subsidies. Republicans have consistently voted to slash funding to the railroad, blocked efforts to fund critical rail infrastructure and circulated plans to take the Northeast Corridor, the nation’s busiest rail corridor, out of Amtrak’s hands.

Trump’s budget proposal in February would have slashed federal aid to Amtrak, including its network in the Northeast Corridor, which stretches from Washington to Boston, by more than half. The plan also sought to phase out aid to Amtrak’s long-distance service.

Trump’s proposed 2021 budget included reductions in funding to the Northeast, to $325 million from $700 million. It proposed to cut funding for Amtrak’s long-distance trains to $611 million from $1.3 billion.

Congress created Amtrak in 1970 to take over intercity passenger rail services previously operated by private companies. The rail infrastructure was already aging then, and investments have been lacking for decades.

Amtrak’s ridership is heavily centered in the Northeast, the corridor between Washington and Boston, and along densely populated areas of the country. Biden for years commuted from Washington to Delaware on Amtrak, and he is a high-profile supporter of the railroad.

Anu Narayanswamy contributed to this report.