President Trump slammed “sneaky Dianne Feinstein” Wednesday after the Democratic senator released the transcript of a congressional interview with the co-founder of the firm behind the anti-Trump dossier, claiming the move was “possibly” illegal. 

“The fact that Sneaky Dianne Feinstein, who has on numerous occasions stated that collusion between Trump/Russia has not been found, would release testimony in such an underhanded and possibly illegal way, totally without authorization, is a disgrace. Must have tough Primary!” Trump tweeted Wednesday.

The fact that Sneaky Dianne Feinstein, who has on numerous occasions stated that collusion between Trump/Russia has not been found, would release testimony in such an underhanded and possibly illegal way, totally without authorization, is a disgrace. Must have tough Primary!

— Donald J. Trump (@realDonaldTrump) January 10, 2018

Feinstein, D-Calif., the ranking member on the Senate Judiciary Committee, unilaterally released the 312-page transcript of Fusion GPS co-founder Glenn Simpson’s August interview with committee investigators.

The release provoked controversy on Capitol Hill, with a spokesman for committee Chairman Chuck Grassley, R-Iowa, slamming Feinstein’s move as “confounding.” Spokesman Taylor Foy said she made the decision without consulting the chairman and warned the move jeopardized other highly sought witness testimony.