Democratic State Senator Ken Gordon has conceded the secretary of state race to state Treasurer Mike Coffman.
Coffman -- the Republican candidate to replace Republican Gigi Dennis as the state's top elections official -- holds a substantial lead in unofficial returns, but workers in Denver and several other counties are still counting ballots.
Unofficial results compiled by The Associated Press show Coffman with a 27-thousand-720-vote lead over Gordon.
Thousands of ballots remain to be counted.
Gordon will remain state Senate majority leader if he loses to Coffman.
Gordon's announcement came during a joint news conference today where he and Coffman said they will launch a bipartisan effort to explore changes in election law.
The vote-counting delay has been blamed on unfamiliarity with new voting equipment, computer failures, a long and complicated statewide ballot and a switch by many big counties to voting centers from the traditional precinct model.