The top Republicans on the House committees leading the impeachment inquiry into President Trump blasted the investigation as “illegitimate” and a “sham” on Tuesday even after Democrats scheduled a vote to formalize the proceedings — signaling Speaker Nancy Pelosi's decision to hold that vote will not assuage the GOP's process complaints.

House Intelligence Committee Ranking Member Devin Nunes, R-Calif., Oversight Committee Ranking Member Jim Jordan, R-Ohio, and Foreign Affairs Committee Ranking Member Michael McCaul, R-Texas, penned a letter to Rep. James McGovern, the chairman of the House Rules Committee who announced his panel would take up an impeachment procedure resolution on Wednesday to “ensure transparency and provide a clear path forward.”

Nunes, Jordan and McCaul accused McGovern, D-Mass., of not giving enough time for Republican members to review the resolution ahead of the vote and continued to blast the inquiry as a whole.

PELOSI ANNOUNCES RESOLUTION ON IMPEACHMENT PROCEEDINGS

“Under House Rules you championed at the beginning of this Congress, major legislation is required to be posted 72 hours in advance of a vote,” they wrote. “Yet, here, on the gravest and most solemn work the House can do, you are forcing the House to consider a resolution with text that is still not available two days before the vote.”

“Without text, we know nothing about the Democrats’ intended impeachment process. Your website describes the resolution as ‘directing certain committees to continue their ongoing investigation,’” they continued. “Chairman Schiff does not need a resolution to continue leaking selective facts from his basement bunker.”

They added: “We can only assume, therefore, that this resolution is necessary to allow Democrats to subvert the ordinary legislative process.”

The fiery statement from them and other Republicans indicates the looming vote will not ease their concerns about the process being used to investigate Trump over allegations he improperly sought a politically related investigation from Ukraine and may have used U.S. military aid as leverage — which the president denies.

Republicans have for weeks complained about closed-door interviews being conducted as part of the probe and the lack of a formal House vote, challenging the legitimacy of the current framework for impeachment proceedings in the absence of one.

McGovern and Pelosi, D-Calif., announced Monday that the House would indeed vote on a resolution to formalize and establish the parameters of the Trump impeachment inquiry. Pelosi made clear that the vote is being conducted because of the Republican complaints.

“We are taking this step to eliminate any doubt as to whether the Trump administration may withhold documents, prevent witness testimony, disregard duly authorized subpoenas, or continue obstructing the House of Representatives,” Pelosi said Monday.

She accused Trump and his GOP allies of holding the position that "because the House has not taken a vote, they may simply pretend the impeachment inquiry does not exist."

The resolution is not an actual article of impeachment, but rather a measure that sets process ground rules.

But in their letter Tuesday, the ranking members went on to allege the resolution “will allow the Committees to ‘side step traditional time limits’ and allow unelected congressional staff additional time during public hearings to question witnesses.”

“The Democrats’ entire impeachment process is fundamentally unfair,” they wrote. “It is rigged. The American people see through this partisan charade.”

They added: “No matter how hard you try to legitimize this sham impeachment inquiry, it cannot hide the Democrats’ goal of relitigating the results of the 2016 presidential election.”

Pelosi announced the Trump impeachment inquiry on Sept. 24, saying at the time that "the president must be held accountable" for his "betrayal of his oath of office, betrayal of our national security, and the betrayal of the integrity of our elections."

The inquiry was opened after a whistleblower complaint alleged that Trump, during a July phone call, pushed Ukrainian President Volodymyr Zelensky to investigate former Vice President Joe Biden and his son Hunter as military aid to the country was being withheld.

Fox News' Alex Pappas contributed to this report.