Groups that fought San Francisco's lawsuit seeking marriage for same-sex couples have asked the California Supreme Court to delay its decision to allow the marriages.

The organizations, including the Proposition 22 Legal Defense Fund and the Alliance Defense Fund, filed a request with the court Thursday afternoon seeking the delay until after the November election. That's when the state's voters will likely decide a proposed constitutional amendment to limit marriage to opposite-sex couples.

"Permitting this decision to take effect immediately - in the light of the realistic possibility that the people of California might amend their constitution to reaffirm marriage as the union of one man and one woman - risks legal havoc and uncertainty of immeasurable magnitude," the filing states.

A spokesman for San Francisco City Attorney Dennis Herrera said they would fight any delay in issuing the marriage certificates to gay couples. Lawyers for the city are expected to file a legal response next week.

Many county clerks believe the gay unions could begin as early as June 16. And although the proposed gay-marriage ban has not officials been put on the November ballot yet, supporters have obtained the necessary signatures.

It is unclear what would happen to gay couples who marry between June and November if the initiative passes.

"It is to no one's benefit to redefine marriage for four or five months," said Andrew Pugno, legal counsel for the Proposition 22 Legal Defense Fund.

Also Thursday, state Sen. Carole Migden, D-San Francisco, announced she had received an oral opinion from the California Legislative Council, the attorney for the state Legislature, stating that same-sex couples do not need to dissolve their domestic partnerships in order to marry.

Read the request for a delay at www.sfgate.com/ZDLX.