Rep. Stephen Lynch (D-Mass.) will announce his special election bid for Democratic Sen. John Kerry’s Massachusetts seat on Thursday, a person close to him has confirmed.

Lynch’s move is not a surprise. Last week, it looked like a near certainty that he would enter the race. His decision will pit him against Rep. Ed Markey, the only other Democrat who has announced his intention to run. Kerry, Senate Democrats’ campaign arm and several prominent Bay State Democrats are all backing Markey.

Kerry was overwhelmingly approved by the Senate on Tuesday to be the next secretary of state. Gov. Deval Patrick (D) will be tasked with appointing a replacement for Kerry, but that person isn’t expected to run in the special election for the remainder of the the senator's term.

WCVB reported that Lynch is scheduled to make the announcement first in Springfield, then in Boston.

The Lynch-Markey matchup will present a stark political contrast. Lynch is a conservative Democrat, while Markey is a liberal Democrat.