GOP Sen. Bob Corker of Tennessee decided he will not run for re-election after reconsidering his decision to retire last year, his chief of staff told reporters Tuesday.
His decision puts an end to months of speculation that he might reverse his decision to retire.
Corker had conversations with a few colleagues earlier this month about whether he should reconsider his decision to not seek re-election this year, GOP sources told CNN.
Corker's decision sets up a likely general election between GOP Rep. Marsha Blackburn Blackburn and former Gov. Phil Bredesen, a 74-year-old Democrat who has won twice statewide before but last ran for office in 2006.
Former Rep. Stephen Fincher had also entered the Republican primary, but dropped out last week, encouraging Corker to run.
News the Corker would stand by his decision to not seek re-election was first reported by Politico on Tuesday.
This story is breaking and will be updated.