(CNN) A Democrat on a key Senate committee tells CNN's Erin Burnett that he will vote no on Donald Trump's nominee for treasury secretary

Sen. Sherrod Brown, D-Ohio, revealed during a prime-time interview from Washington DC, that he will oppose Steven Mnuchin for the cabinet post.

Brown spent much of Thursday grilling Mnuchin during a confirmation hearing before the Senate Finance Committee.

Following that testimony on the eve of Trump's inauguration, Burnett asked Brown for his official position on the nominee.

"I'm going to vote no on his confirmation," Brown said, before lobbing a thinly veiled barb at Trump's cabinet picks in general -- and Mnuchin in particular.

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