Senate Majority Leader Mitch McConnell (R-Kentucky) on Tuesday rejected Democratic lawmakers’ calls to subpoena John Bolton, Mick Mulvaney and other top current and former White House aides to testify in President Donald Trump‘s potential Senate impeachment trial.

McConnell’s decision comes just one day before House lawmakers are set to vote on whether or not to charge Trump with abuse of power and obstruction of Congress, both of which they are expected to vote in favor of. Senate Minority Leader Chuck Schumer (D-New York) was one of several Democrats who called for White House Chief of Staff Mulvaney and former National Security Adviser Bolton to appear as witnesses for Trump’s trial in the Senate, as the pair have firsthand knowledge of the president’s actions involving Ukraine. Schumer also called for two of Mulvaney’s aides, senior adviser Robert Blair and Office of Management and Budget official Michael Duffey, to testify.

“It is not the Senate’s job to leap into the breach and search desperately for ways to get to ‘guilty,’” McConnell said Tuesday morning on the Senate floor. “That would hardly be impartial justice.”

“If House Democrats’ case is this deficient, this thin, the answer is not for the judge and jury to cure it here in the Senate,” the Kentucky Republican added. “The answer is that the House should not impeach on this basis in the first place.”

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McConnell also accused Schumer of attempting to create a “completely new set of rules” for Trump. The Senate Majority Leader insisted he would like to see two resolutions: one that addresses impeachment procedures and another that outlines possible witnesses, similar to former President Bill Clinton‘s impeachment trial.

“The same process that Senator Schumer thought was good enough for President Clinton he doesn’t want to afford President Trump, go figure,” McConnell added.

However, some Republicans, like Rep. Francis Rooney (R-Florida) — a member of the House Foreign Affairs Committee — urged McConnell to let Bolton and Mulvaney testify before the Senate.