BROOKLYN - Sen. Charles Schumer announced that he will back Ken Thompson for Brooklyn district attorney today at Borough Hall.

The announcement comes one day before District Attorney Charles Hynes was expected to announce that he will campaign to keep his post. Hynes’ spokesperson confirmed that he will actively campaign despite losing to Thompson during the democratic primary.

At the time, Hynes said that he would help Thompson transition into the office. Now, he will run on the Republican ticket against him.

Hynes has been the Brooklyn district attorney for more than two decades.