Rep. John Boozman (R-Ark.) is informing his soon-to-be opponents that he will run for Senate, according to an Arkansas source.

Boozman has been publicly weighing a challenge to Sen. Blanche Lincoln (D-Ark.) since last week. He will join a field that includes state Sen. Gilbert Baker and several other Republicans.

His entry will also open up the third Arkansas House seat this month, paving the way for a revamping of the state's four-member House delegation. Reps. Vic Snyder (D-Ark.) and Marion Berry (D-Ark.) both announced their retirements recently.

Boozman's office could not immediately be reached for comment, but it said Wednesday that he would make a decision by Friday.