The Managing Director of the Australian Christian Lobby, Jim Wallace, hopes the petition, which was set up as a joint effort between the ACL and the Australian Family Association (AFA), will reach 100,000 signatures by this weekend.
"In five weeks we've had this extraordinary display of unity amongst Australians that marriage is the union of one man and one woman, voluntarily entered into for life," he said.
"However, we know that the opponents of marriage have a well funded campaign that is seeking to present a larger petition. We need all Christians to make these last few days before the conference count by getting knowledge of this petition out to friends," he said.
"The petition will send a clear message to the ALP Conference that marriage is a vote changing issue for many Australians and they want governments to politically support a family structure that confirms the importance of motherhood and fatherhood in a child's life," he said.
For more information, visit australianmarriage.org.au/petition