Updated

A coalition of religious and family groups kicked off a drive Wednesday to amend the state constitution to ban gay marriage.

Coloradans for Marriage submitted a proposed amendment that defines marriage between a man and a woman to the state Legislative Council office, the first step toward getting it on the ballot this fall. The group will need the secretary of state to approve the wording and 68,000 valid signatures of registered voters to get the measure on the ballot.

The group's president, Bishop Phillip H. Porter Jr., said the proposed amendment is about preserving marriage and protecting children, not about hating gay people.

An opposing group, Coloradans for Fairness and Equality, argues the proposal does not strengthen or protect marriage and enshrines "discrimination into the language of the constitution."

There are currently 18 states with constitutional amendments against gay marriage. Most of those amendments were adopted after Massachusetts' highest court legalized gay marriage in 2003.