Former Sen. George LeMieux (R) is expected to formally announce a run against Sen. Bill Nelson (D) next week, according to a report in the St. Petersburg Times.

In August 2009, LeMieux was appointed to serve the remainder of former Sen. Mel Martinez’s term after the Republican retired. LeMieux left office in January and joined a law firm.

In seeking the seat, LeMieux ensures there will be a GOP primary, joining a field that already includes state Senate President Mike Haridopolos and will likely include former state Rep. Adam Hasner, a favorite of grass-roots conservatives. Rep. Connie Mack IV announced last week that he would not join the race.

Democrats hope the primary will be both expensive and bloody. Republicans see the race as a top pickup opportunity given that Nelson is the only Democrat that still holds statewide office in Florida.

LeMieux has moved to distance himself from failed 2010 Senate candidate and former Gov. Charlie Crist, who is unpopular with the Republican base. But LeMieux’s connections to Crist run deep — as a former chief of staff and campaign manager. LeMieux also owes his Senate appointment to Crist.

Polling released earlier in the week gave Nelson a strong lead over LeMieux and other prospective candidates, but the survey also suggested that Nelson is vulnerable.