With election season heading into its final stretch, the four City Council candidates endorsed by the group Palo Altans for Sensible Zoning are urging others in the race to join them in a pledge to keep campaigning positive.

Tom DuBois, Eric Filseth, Karen Holman and Lydia Kou issued a statement over the weekend inviting the other eight candidates to join them for a 5 p.m. ceremony before tonight's council meeting to make statement "to publicly re-affirm your commitment to positive campaigning and publicly acknowledge our shared responsibility to ensure the public discussion is focused on issues."

"We all share a common interest in an open, honest and fair elections," the four candidates said in a statement, which is also co-signed by school board candidate Ken Dauber. "We have a long and proud tradition in our community of campaigns that are focused on the issues of concern to our citizens, conducted in a way that respects the democratic process and enables voters to make informed decisions."

The three non-incumbent council candidates are all members of Palo Altans for Sensible Zoning, a citizens group that was formed last year in opposition to a housing development on Maybell Avenue. The group now advocates for slow-growth policies, including opposition to "upzoning" sites in residential areas. While Holman, an incumbent, is not a member of the group, she is a longtime skeptic of new developments and has been endorsed by the citizens group.

Their pledge to campaign positively notwithstanding, the citizens group has not been shy about painting the other incumbents in the race – Greg Scharff and Nancy Shepherd – as pro-development and anti-resident. Last month, the group released a scoresheet in which it selected 20 votes that the council has taken in the last two years and broke them down into "resident-favorable" and "resident-unfavorable" categories. In most cases, votes in favor of new developments (including ones like the redeveloped Edgewood Plaza, which had broad neighborhood support) were characterized as unfavorable to residents.

The scoresheet, which was widely distributed as a campaign flier, gave Holman and Greg Schmid the highest scores while Scharff and Shepherd ranked near the bottom, just above Larry Klein and Gail Price.

Now, the candidates affiliated with the group that distributed the scoresheet attribute their decision to hold the Monday event to the "recent negative campaigning," including some recent unsubstantiated rumors that DuBois and Filseth are affiliated with libertarianism and the Tea Party (both have denied these rumors). The candidates also called on their supporters to familiarize themselves with the California Code of Fair Campaign Practices, which explicitly prohibits whisper campaigns, character defamation and "any dishonest or unethical practice that tends to corrupt or undermine our American system of free elections."

Several candidates have already indicated that they don't plan to participate in the 5 p.m. event. A.C. Johnston, an attorney whose voting record has been questioned by supporters of other candidates, said in his response to the group's email that he had signed the Code of Fair Campaign Practices in August when he filed papers to run for council.

"I don't see any need to sign it yet again," Johnston said. "Since declaring my candidacy, I and my campaign have consistently adhered to the provisions of the Code, and we will continue to do so even though I feel that I have been subject to unfair attacks by supporters of other campaigns."

Nancy Shepherd likewise said that she has already committed to a positive campaign, even though it became clear early in the campaign that she would be subject to attacks on her record and character. She said she and her campaign had agreed months ago that they would run an "ethical" campaign.

"Critics suggested that I did not care about neighborhood interests and labeled me as 'pro-developer' and 'pro-growth,'" Shepherd said in a statement. "However, these labels are not accurate. My record reflects that I have been balanced in weighing each issue on its merits and I have always voted for what I sincerely believe is in the best interests of Palo Alto. I am keenly aware of the emotional tactics of fear and outrage being used in this campaign by other candidates. I refuse to participate."

Shepherd said that because she has already signed the voluntary pledge of ethics and because she has "not made any attacks on other campaigns nor printed any material misrepresenting other candidates' positions, I find it unnecessary to sign this pledge of campaign ethics a second time."

Catherine Crystal Foster, who is one of five candidates seeking a seat on the school board, also said that her committee has "run a positive, ethical campaign from day one, and we continue to be fully committed to running an ethical campaign with a positive message." She said she had "gladly signed" the fair campaign practices pledge when she filed her candidacy papers and has abided by the pledge ever since.

"I deplore negative campaigning of any kind," Foster said.