SAN FRANCISCO — The federal judge who overturned California’s same-sex marriage ban has more bad news for the measure’s backers: He doubts they have the right to challenge his ruling that gay couples can begin marrying next week.

Chief U.S. District Judge Vaughn R. Walker on Thursday rejected a request to delay his decision barring Proposition 8 from taking effect until high courts can take up an appeal lodged by its supporters. One of the reasons, the judge said, is he’s not sure the proponents have the authority to appeal since they would not be affected by or responsible for implementing his ruling.