Committee Chairman Bryan Steil (R-WI) issued the subpoenas to leaders at the Departments of Labor, Justice, Housing and Urban Development, Health and Human Services, and Agriculture, asking them to appear before the committee at various dates in early September, according to copies of the subpoenas reviewed by the Washington Examiner.

Steil said in a statement that the agencies had “refused to comply” with the committee’s monthslong investigation into the matter.

“These Biden Administration agencies failed to produce their strategic plans to implement Executive Order 14019 on multiple occasions,” Steil said. “It’s time that these officials explain to the Committee what is in these plans, and how their agencies are implementing their plans.”

The executive order at issue, which President Joe Biden signed in March 2021, directs government agencies to encourage more people to register to vote.

In the months leading up to the 2024 election, the order has drawn scrutiny after reports, including from the Washington Examiner, revealed that the Biden administration was engaging with left-wing activists on how to implement the order and expand voter registration access.

The order calls for “soliciting and facilitating approved, nonpartisan third-party organizations and state officials to provide voter registration services on agency premises.”

However, it is unclear which organizations the administration is using to provide the voter registration services. In letters to the five officials he subpoenaed, Steil said he has concerns that the executive order could result in Hatch Act or National Voter Registration Act violations because of its potential to improperly benefit Democratic candidates.

Republican lawmakers, including Steil and House Oversight Committee Chairman James Comer (R-KY), are among several people and groups who have raised alarm over the executive order, which has become known as “Bidenbucks” in Republican circles. The term is a play on the nickname “Zuckerbucks,” a reference to tech billionaire Mark Zuckerberg donating hundreds of millions of dollars to election infrastructure in 2020, including in key battleground states that saw close races. A right-leaning group found in an analysis that the massive private donations may have improperly swung the election in favor of Democrats.

The conservative Heritage Foundation’s Oversight Project has made Freedom of Information Act requests over Biden’s executive order. The group found that the administration has withheld documents that would show details of how agencies have implemented the executive order by asserting privilege over the documents.

Kyle Brosnan, chief counsel at the Oversight Project, told the Washington Examiner the executive order is “nothing more than a mobilization of the federal government to support” Vice President Kamala Harris’s campaign. Brosnan said he believes the order has led to federal government officials using tax dollars to boost voter registration of Democrats.

“The Biden-Harris Administration has worked exclusively with ideologically-aligned NGOs and state officials to use your tax dollars to register left-leaning voters and has obstructed all efforts at gaining transparency about the EO’s implementation,” Brosnan said.

The ramped-up pressure from congressional Republicans and think tanks like Heritage follows nine Republican attorneys general filing a lawsuit in August to halt the executive order.

The Washington Examiner reached out to the White House for comment.