Republican congressman Jim Jordan told the House select committee investigating the Capitol attack that he would consider complying with the panel’s subpoena only if they shared the material that put him under scrutiny, according to a letter he sent Wednesday.

The response by Jordan – the top Republican on the House judiciary committee who spoke to Donald Trump on January 6 – stopped short of a refusal to comply with his subpoena, though it was not clear how he would proceed if the panel refused his request.

In the six-page letter sent to the select committee and obtained by the Guardian, Jordan demanded House investigators share with him all materials they intended to rely upon in questioning, materials in which he is referenced, and legal analyses about subpoenaing members of Congress.

“Because your subpoena is an unprecedented use of a committee’s compulsory authority against another member,” Jordan said in his letter, “I respectfully ask for the following material so that I may adequately further respond to your subpoena.”

The response puts the ball in the select committee’s court, forcing House investigators to decide whether they will acquiesce to Jordan’s demands in the hope that it convinces him to give some testimony, or refuse and potentially close off any chance of cooperation.

But the letter, which challenged the legality of the select committee and its subpoenas, appeared to be something of a gambit for Jordan, too. For one thing, it was not clear whether Jordan wanted to face the consequences for defying a subpoena if his demands were not met.

The response from Jordan – finalized on Tuesday and sent to the panel on Wednesday – also included complaints that House investigators had not acted in good faith by issuing a subpoena around four months after Jordan apparently declined to give voluntary assistance.

“Your subpoena was unprompted and, in light of the unaddressed points from my January 9 letter, plainly unreasonable. I write to strongly contest the constitutionality and validity of the subpoena in several respects,” Jordan said.

The select committee’s subpoena to Jordan – which came alongside four other subpoenas to House minority leader Kevin McCarthy, Scott Perry, Andy Biggs and Mo Brooks – demanded testimony about his December 2020 meetings with Trump in the White House and other communications.

House investigators took the step to issue the unprecedented subpoenas to five Republican members of Congress after Jordan, McCarthy and Perry did not appear for interviews on tentative dates suggested in initial letters seeking voluntary cooperation.