Opponents of a controversial ballot measure to limit hotel development in Sonoma were clinging to a narrow 92-vote lead Wednesday after Tuesday's special election, with an additional 308 ballots still outstanding.

County election officials said in order for Measure B proponents to make up the deficit, they'd have to win about 66 percent of the remaining votes.

Still outstanding are 244 mail-in ballots that were dropped off at a polling place in Sonoma on Tuesday, as well as 64 provisional ballots.

Election officials said they are hoping to have a final count completed by early next week.

Larry Barnett, the main backer of the initiative, said Wednesday that the deficit represents a "high hurdle" for supporters of the measure to overcome.

"It would be a fairly radical departure to jump from the percentages we saw when they (voting results) first came out," Barnett said.

Nancy Simpson, campaign coordinator of the organized opposition group Protect Sonoma, could not immediately be reached Wednesday.

Members of the group Tuesday night expressed confidence that the vote results would stand and that Measure B had been turned down.

Of the votes cast, 2,887 were mailed in, while 736 voters went to the polls. The city has 6,457 registered voters.

The Hotel Limitation Measure would cap new hotels or expansion of existing ones at 25 rooms unless Sonoma achieves an annual occupancy rate of 80 percent, which the city has never done. In 2012, the rate was just under 65 percent.

Proponents said the initiative would help preserve Sonoma's quality of life, while opponents argued it would chill economic growth.