The House select committee investigating the Capitol attack on Friday issued subpoenas to lead participants in an audacious scheme to send fake Trump slates of electors to Congress.

The development comes as the panel seeks to learn whether the plan was coordinated by the Trump White House.

The fake certificates – which falsely declared Donald Trump the winner of the 2020 election, though the states had officially declared otherwise – are significant as they appear to have been a central tenet of the former president’s effort to return himself to power.

The fake slates of electors were sent to Congress from seven contested states that were in fact won by Joe Biden. Trump and his allies might have hoped to use them as justification for having Biden’s wins in those states rejected.

Congressman Bennie Thompson, the chairman of the select committee, said that he had authorized subpoenas to 14 Republicans who were listed as the chairperson and the secretary of each group of “alternate electors” in order to learn how the scheme was coordinated.

The move by the select committee comes days after the deputy attorney general, Lisa Monaco, confirmed that the justice department had opened an investigation into the scheme, raising the stakes for the fake electors and any Trump White House aides who may have been involved.

Thompson issued subpoenas to the two most senior Republicans who signed onto the fake certificates in Arizona, Georgia, Michigan, New Mexico, Nevada, Pennsylvania and Wisconsin, including several prominent current and former state Republican party leaders.

The subpoena targets included: Nancy Cottle, Loraine Pellegrino, David Shafer, Shawn Still, Kathy Berden, Mayra Rodriguez, Jewll Powdrell, Deborah Maestas, Michael McDonald, James DeGraffenreid, Bill Bachenberg, Lisa Patton, Andrew Hitt and Kelly Ruh.

Trump’s plan to return himself to office rested on two elements: the existence, or possible existence, of alternate slates, and then-vice president Mike Pence using the ambiguity of “dueling slates” for Trump and Biden to reject those results at Biden’s certification.

The effort to subvert the results of the 2020 election at the joint session of Congress on 6 January fell apart after Pence refused to abuse his ceremonial role to certify the results, and it was clear the “alternate slates” were not legitimate certificates.

But in some cases, top officials, such as Republican National Committee members Berden and DeGraffenreid and former state GOP chairs Hitt and Maestas, signed the fake certificates that used official state seals and sent them to the National Archives.

“The phony electors were part of the plan to create chaos on Jan. 6,” said congressman Jamie Raskin, a member of the select committee. “The fake slates were an effort to create the illusion of contested state results,” as “a pretext for unilateral rejection of electors.”

The panel is seeking to examine whether the effort was coordinated by the Trump White House and whether it amounted to a crime, according to a source familiar with the investigation. The subpoenas compel the production of documents and testimony through February.