Federal Reserve Governor Jerome Powell stepped up the central bank’s push against what he termed congressional efforts to extend political influence over monetary policy, calling them “misguided” and “in violent conflict with the facts.”

Existing law exempts Fed monetary policy from Government Accountability Office audits because that would include “substantial risk of political interference,” Powell said on Monday in a speech in Washington. A bill by Republican Senator Rand Paul of Kentucky would eliminate the exemption.

Powell’s speech marked an escalation in the Fed’s public campaign to thwart congressional pressure, which Philadelphia Fed President Charles Plosser called “scary” in separate remarks on Monday. Dallas Fed chief Richard Fisher argued that the central bank was already “audited out the Wazoo.”

The unusually sharp remarks suggest policy makers see an increasing threat from Republicans, who now control both the Senate and House of Representatives. President Barack Obama could veto any anti-Fed legislation that reached his desk, implying little chance such proposals would become law unless Republicans recapture the White House in 2016.

Fed Chair Janet Yellen, who told reporters in December she’ll speak out “forcefully” against monetary-policy audits, delivers her semi-annual testimony to Congress on Feb. 24-25.