Washington CNN  — 

Rep. Doug Collins, the top Republican on the House Judiciary Committee, is telling a federal judge that the Democrats’ impeachment investigation has no legal basis.

In a proposed amicus brief filed Thursday with a federal judge in Washington, Collins says the court should reject a request by the Democratic-led Judiciary Committee to see information from the secret grand jury used in former special counsel Robert Mueller’s investigation.

Collins reiterates the GOP’s argument that the full House must vote to authorize an impeachment inquiry, and it has not done so.

“If the Committee seeks judicial interference in its proceedings, the House must take the procedural and political action required of it by holding a vote to delegate its impeachment power to the Committee,” Collins wrote. “Barring such action, the Committee advances an unprecedented and untested audience.”

House Speaker Nancy Pelosi announced last month that several Democratic-led committees would conduct impeachment-related investigations. That declaration, Collins says, does not pass muster as a legal basis.

“Her statement has no legal effect; the Speaker’s press conferences do not provide her extra-legislative authority,” Collins wrote.

In their request for the grand jury information, the Democrats said in their filing earlier this week that Congress needs it for the impeachment probe.

Grand jury confidentiality has a high bar for access, but in this case, the judge’s decision could come down to the needs of the House and Senate in a “judicial proceeding,” such as impeachment.

Details in the Mueller report about Russian interference in the 2016 election and possible efforts by the President to obstruct that investigation “may also be relevant to the House’s investigation of the President’s solicitation of Ukrainian interference in the 2020 election,” House Democratic lawyers wrote.

Thursday, Collins said the request is too broad and unwarranted.

“Without a proper foundation, the Committee is asking the Court to exercise the extraordinary action of intervening on behalf of one branch against the protected privacy of a group of American citizens, safeguarded by another branch,” he wrote.