AUGUSTA — Maine Citizens for Clean Energy announced this afternoon they will try to qualify for the 2013 — rather than the 2012 — ballot because they “didn’t have enough of a margin” to be sure they’d have the required 57,277 signatures.

“One more week likely would have been enough,” said spokesman David Farmer. “We’re that close.”

Earlier today, the group canceled a press conference to discuss whether to move forward. It faced a 5 p.m. deadline to deliver the signatures to state election officials.

The referendum proposal would have required that at least 20 percent of Maine’s electricity come from renewable energy sources, such as wind, tidal and solar, by 2020, and that utilities invest in energy efficiency whenever it would reduce energy costs for ratepayers.

Gov. Paul LePage had been a vocal opponent of the effort, saying he believed it would increase costs.