Louisville Metro Councilman Hal Heiner is expected to announce his candidacy for mayor Tuesday morning.
Heiner, who represents the 19th district in eastern Louisville, will be the second Republican to enter the 2010 race. The other is Louisville developer Chris Thieneman.
Heiner will have to give up his council seat, which is also up for election next year.
Five Democrats have announced for mayor. They are: Metro Councilmen Jim King and David Tandy, businessmen Tyler Allen and Greg Fischer and west Louisville resident Connie Marshall.
Coffee shop owner Nimbus Couzin is running as an independent.
Current Mayor and Democrat Jerry Abramson is not seeking a final term in order to run for Lt. Governor in 2011.