The Colorado Secretary of State's office says the so-called "personhood" amendment will not be on the November ballot, despite any legal action from proponents to prove they collected enough voter signatures.
Secretary of State spokesman Andrew Cole tells the Denver Post the deadline for ballot certification was Monday. Even if a judge rules personhood sponsors' petition was sufficient, the measure would have to wait for the 2014 general election.
Secretary of State Scott Gessler announced last month that backers of amendment 46 fell about 3,900 valid signatures short of the some 86,000 needed.
The measure would amend the state constitution to extend protection of life to "all human beings at any stage of development."
Similar abortion bans on Colorado ballots in 2010 and 2008 elections failed. The measure has steadily lost momentum since 2008. Each year, fewer people have signed the petition to put the measure on the ballot, and Coloradans have voted against it by three-to-one margins.