Fusion GPS co-founder Glenn Simpson is rejecting a subpoena from the House Judiciary Committee and his lawyer has informed the panel he intends to “invoke his constitutional rights not to testify.”

Simpson’s lawyers, led by Joshua Levy, said the committee “is not designed to discover the truth,” and that his client will not appear before them on Oct. 16 for a closed-door deposition as requested.

“Consistent with the Sept. 27, 2018 letter we sent to you, Mr. Simpson, whose testimony is a matter of public record, will not be participating in a confidential deposition before this committee,” the lawyers wrote in a letter to Judiciary Committee Chairman Bob Goodlatte, R-Va., according to media reports.

“He will instead invoke his constitutional rights not to testify under the First and Fifth Amendments of the Constitution,” they said.

Fusion GPS was hired to conduct opposition research by a lawyer who represented the Democratic National Committee and Hillary Clinton’s campaign. The firm then hired former British intelligence officer Christopher Steele, who authored the so-called "Trump dossier," which contained scandalous claims about President Trump's ties to Russia and was partially used to receive a surveillance warrant on a Trump campaign aide.

Simpson’s lawyers criticized the panel, and blamed the GOP members for trying to “ruin the reputations of some of the government’s most dedicated and experienced civil servants,” in order to “weaken the independence of this Justice Department.”

“The obvious — and at times explicitly stated — goal of this committee is to discredit and otherwise damage witnesses to Russia’s interference in the 2016 election, all as part of an effort to protect a president who has sought to placate and curry favor with a hostile foreign power and who demands that the Justice Department stop investigating him,” the lawyers said.

The letter elicited backlash from some Republicans on the committee, including Rep. Mark Meadows of North Carolina.

“Rod Rosenstein doesn’t show today. Now Fusion's Glenn Simpson reportedly takes the Fifth,” Meadows tweeted Thursday evening. “At some point, we have to realize: the problem has never been President Trump. The problem is the coordinated effort to undermine him... and those who will stop at nothing to cover it up.”

[Previous coverage: Fusion GPS contractor Nellie Ohr, wife of DOJ official Bruce Ohr, to testify to Congress this week]

Simpson’s lawyers previously rejected an invitation to appear before the House Judiciary and Oversight committees late last month, noting that Simpson has previously provided more than 20 hours of testimony to the Senate Intelligence Committee, the Senate Judiciary Committee, and the House Intelligence Committee.

Simpson has previously met with the panels as part of their investigations into Russian interference in the 2016 election and whether the Trump campaign colluded with the Kremlin.