Keith Christensen is the first to brandish a knife in the race for Salt Lake City mayor, swiping at fellow candidates in mailers about renovations of Pioneer Park and their qualifications for the office.

One mailer sent out this week by Christensen's campaign features a picture of a Band-Aid and criticizes candidates Dave Buhler and Jenny Wilson for favoring a "band-aiding" approach to solving the problems at Pioneer Park.

Another new flier compares Christensen's credentials with those of the other top-tier candidates — Wilson, Buhler and Ralph Becker — and attempts to call into question their ability to lead Utah's capital city.

The mailers are the closest thing to negative campaigning to emerge in the race to replace Mayor Rocky Anderson. For the most part, candidates have been content to tout themselves, their qualifications and their views on city issues in campaign ads and literature.

According to the candidates, the two mailers from Christensen's campaign are the first to single out other candidates by name.

Christensen, a former Salt Lake City councilman and Anderson's choice as his successor, defended the mailers in an interview, calling them educational pieces, not negative campaigning.

"It tells people what I think vs. what other candidates think," Christensen said, specifically referring to a mailer about Pioneer Park. "It's important to understand the differences between (the candidates). If I don't talk about the differences, I don't know who will."

Wilson and Buhler call Christensen's shift in campaign tactics an act of desperation as Tuesday's primary election nears.

"If you look at the public opinion polls, Keith has the furthest to go," said Wilson, a Salt Lake County councilwoman and the front-runner in the race, according to polls conducted for the Deseret Morning News.

"I wouldn't put this in the negative-campaigning category," she said. "It's pretty innocent stuff, but it's also a little sophomoric. It seems to me the better strategy for Keith Christensen — and all candidates — would be to promote themselves."

Buhler calls the recent mailings disappointing, saying he thought Christensen would run "a more high-level campaign."

"It's unfortunate that Keith has decided he needs to do a negative mailing," the Salt Lake City councilman said. "I'm sorry to see him get desperate to where he would do that."

Buhler said he views the two mailers as the second and third waves of attacks against him by Christensen's campaign. The first wave, he said, came Aug. 29 when Anderson criticized him in an interview with the Deseret Morning News, saying Buhler would be a "disaster" as his replacement.