Senate Finance Committee chair Chuck Grassley (R-IA) defended the whistleblower at the center of President Donald Trump’s Ukraine scandal on Tuesday.

Without explicitly mentioning Trump, Grassley pushed back against the President’s demands to “find out” the identity of the whistleblower who revealed Trump’s attempt to pressure the Ukrainian government to investigate 2020 rival Joe Biden.

Grassley has long championed whistleblower rights, having co-sponsored legislation to expand protections for whistleblowers and even publishing an op-ed as recently as July praising whistleblowers’ “critical part in Congress’s oversight efforts.”

“This person appears to have followed the whistleblower protection laws and ought to be heard out and protected,” Grassley said in an official statement on Tuesday. “We should always work to respect whistleblowers’ requests for confidentiality.”

The Republican senator slammed “uninformed speculation wielded by politicians,” saying that such speculation is “counterproductive and doesn’t serve the country.”

Grassley also corrected Trump and his allies’ claim that the whistleblower’s complaint was somehow illegitimate because it contained second-hand information.

“Complaints based on second-hand information should not be rejected out of hand, but they do require additional leg work to get at the facts and evaluate the claim’s credibility,” he said.