A proposal to ban abortion will be on the Colorado ballot this fall after a state pro-life group submitted more than the required number of signatures.

The proposal was presented by Personhood USA, which is pushing similar measures in 40 other states this year.

"This is more volunteer signatures than we turned in 2008. It's clearly growing. It's clearly getting stronger. We're very excited and looking forward to getting on the ballot," Keith Mason, co-founder of Personhood USA, said.

The ban would give unborn babies human rights in the state constitution from the beginning of conception.

Colorado rejected a comparable measure in 2008.