(CNN) - Denver Mayor John Hickenlooper will formally enter the race for Colorado governor Tuesday, a Democratic source confirms to CNN.
Hickenlooper's decision gives Democrats a strong chance of keeping the seat after Gov. Bill Ritter announced last week that he would not seek a second term.
Hickenlooper has been talking to national Democrats about running for the seat since Ritter said he was going to retire. Last Thursday, Hickenlooper won the endorsement of Ken Salazar, the former Colorado senator who now serves as President Obama's Interior Secretary.
"John Hickenlooper is a uniter," Salazar said in a statement. "If he decides to run, he will make an excellent Governor for the State of Colorado."
Former Colorado House Speaker Andrew Romanoff is reportedly considering dropping his Democratic primary challenge to Sen. Michael Bennet to run for governor.
Former Rep. Scott McInnis is the likely Republican gubernatorial nominee.
- CNN Deputy Political Director Paul Steinhauser contributed to this report