Stonewall has reported two members of Bromley Council to the regulatory Standards Board for England after they made what the gay equality organisation has called "Neanderthal insults" about same-sex partnerships.
Councillor Colin Bloom reportedly labelled gay marriage "immoral", and councillor Joan Wykes said same-sex partnerships don't contribute to "anything apart from trying to get what perks they can".
The council recently reversed a decision to ban same-sex ceremonies when the Civil Partnership Act comes into effect in December.
"We're delighted at the climbdown," said Ben Summerskill, chief executive of Stonewall. "However, we're deeply saddened that Bromley councillors have chosen to use the gay community as a cheap political football."