Annise Parker, the frontrunning candidate for Houston’s mayor, is the subject of a campaign by a conservative group to discourage residents from voting from her.

Parker has been open about her sexuality but has sought to emphasise her credentials for the position, rather than being the ‘gay candidate’.

She has won election as a city official six times and is currently city controller. She came top out of the candidates in a recent vote but the race has now gone to a run-off between her and former city attorney Gene Locke. The mayor must be elected with a majority.

A small group of religious and conservative groups in the city have said they are concerned about a “gay takeover” of city hall and will begin a mail campaign to discourage voters from selecting Parker. Two other candidates in the five remaining city council races are also gay.

They also believe she may grant employee benefits to domestic partners of gay and lesbian city workers. Parker has said she has no plans to do this currently, but admitted she would have to offer the benefits “at some point”.

Dave Welch, executive director of the Houston Area Pastor Council, told the Houston Chronicle: “The bottom line is that we didn’t pick the battle, she did, when she made her agenda and sexual preference a central part of her campaign.

“National gay and lesbian activists see this as a historic opportunity. The reality is that’s because they’re promoting an agenda which we believe to be contrary to the concerns of the community and destructive to the family.”