(CNN) -- Despite headlines saying that it lost Tuesday's vote, the fate of California's proposed $1-a-pack tax hike on cigarettes is still in limbo, and state officials said late Thursday that a final result is likely weeks away.
The tax increase, known as Proposition 29, would raise an estimated $735 million a year, with roughly three-quarters of that money going to cancer research.
Initial results showed Prop 29 being rejected by a margin of roughly 65,000 votes, out of nearly 4 million cast -- a margin of 50.8% to 49.2%. However, the results don't yet include a vast number of mail-in ballots and provisional ballots.
As of Thursday night, at least 829,863 votes were yet to be counted, according to figures posted by California's Secretary of State. The real figure is likely much higher, as the official "uncounted" number leaves out several counties that have yet to send their data.
"We've asked counties to report their number of unprocessed ballots, but it's voluntary, so there's no way to know the exact number," said Allie Schembra, a spokeswoman for the Secretary of State's office. State law requires county elections officials to report final vote tallies by July 6. California Secretary of State Debra Bowen then has until July 13 to certify the results.
As more results trickled in by Thursday night, the margin had shrunk to less than 53,000 votes. Or as one Bay Area Weekly joked, "Proposition 29 results are close enough to make you want to chain smoke."
"Supporters of Prop 29 are not conceding defeat," vowed Doug Ulman, CEO of the Lance Armstrong-founded Livestrong organization. "We will closely monitor the counting of late absentee and provisional ballots... This race is still too close to call, and we remain hopeful that the victory will ultimately be ours."
Proposition 29 was the subject of a fierce advertising campaign, playing out on Californians' television screens for weeks ahead of the vote.
Supporters, including Livestrong, the American Cancer Society, the American Lung Association and New York Mayor Michael Bloomberg, spent about $12 million.