Both mayoral candidates for the upcoming mayoral election in the city of San Diego, California, offer a step forward for the city.

If Councilman Carl DeMaio wins, San Diego, the eighth largest US city, would be the largest to elect an openly gay Republican leader, reports the Associated Press.

The other frontrunner for the seat is Representative Bob Filner, 70, who would be the first Democratic San Diego mayor for almost forty years.

Councilman DeMaio, if elected, as well as being an openly gay mayor of a major city, would also be one of few young Republicans elected to high office in the state of California.

The openly gay councillor was last week endorsed by Bonnie Dumanis, who came forth in the mayoral primary for the same seat, and who was also openly gay.

Both Ms Dumanis and Mr DeMaio were not previously known for gay rights campaigning, and the fact that they were open about their sexuality rarely came up in the media.

San Diego City Hall has for a long time been controlled by moderate Republicans, and a win for Bob Filner would be seen as noteworthy for the Democratic party.

The city’s current Republican mayor, Jerry Sanders, had been previously involved in campaigning for equal marriage. In August, he spoke on a television advert which aired in Tampa, Florida, during the Republican National Convention, reaffirming his stance on equal marriage, and said the party was “changing” on the issue.

Mayor Sanders was also co-chair of a coalition, Mayors for the Freedom to Marry, which included seventy US mayors who joined together in January with a view to increasing the pressure on President Barack Obama and to achieve full support of equal marriage rights nationwide.