Richard Painter, a former chief ethics lawyer in George W. Bush’s administration, will challenge incumbent Minnesota Sen. Tina Smith this year as a Democrat.

Painter, who had previously formed an exploratory committee for a Senate run, will announce his candidacy in a news conference on Monday, his campaign announced.

Richard will be making an important announcement on Monday regarding his involvement in the U.S. Senate election in Minnesota. Stay tuned. pic.twitter.com/9fVEBxnoXq — Painter For Minnesota (@RWPMinnesota) April 26, 2018

Painter will challenge Smith in the Democratic Farm-Labor Party primary.

Smith was appointed by Gov. Mark Dayton to the seat after the resignation of former Sen. Al Franken.