The council voted 4-0 to approve the resolution. The votes included three of Reardon's fellow Democrats and a Republican.
Council member Stephanie Wright, a Democrat, was absent. The resolution asked Reardon to step aside temporarily until the Washington State Patrol finishes its probe.
"This action does not come easily," said Councilman Dave Somers, a Democrat who introduced the resolution and also played a key role last year in bringing allegations about Reardon to the attention of law enforcement. "We've been embroiled in controversy over the last several months."
Somers said he originally had hoped the investigation would proceed quietly until detectives reached their conclusions, perhaps by spring. That's no longer possible, he said.
Reardon was not present for the vote. Neither were members of his staff.
Within minutes, he posted a 34-second YouTube video on his Facebook page. Reardon didn't directly address the council's request that he go on leave, but he left little doubt that he has no plan to step aside.
Reardon said he is focused on "the issues that the people in Snohomish County care about," including jobs and running government efficiently.
"That is the commitment that I made to the people of Snohomish County and I intend to keep it," he said. "And I stand ready to work with anyone, including the Snohomish County Council, to get the job done."
If Reardon does at some point go on leave, his duties, under the county charter, would fall to Deputy Executive Gary Haakenson. Haakenson served 11 years as Edmonds mayor before Reardon appointed him in 2010. He also co-founded the Zumiez clothing store chain.
The County Council lacks the authority to place Reardon on leave.
Before Wednesday's vote, Somers said, "If we did, I would be asking for the county to take that action."
Democratic Councilman Dave Gossett, in remarks before the vote, said he found himself in a position where he'd rather not be. Asking Reardon to step back is appropriate now, Gossett said, because "rumors and allegations have been replaced by a documented list -- a long list -- of legal concerns."
He added, "Any county employee in a similar situation would be required to go on administrative leave. Aaron Reardon is a county employee and the taxpayers deserve that he be treated as any other county employee."
The other council members voting for the resolution were Republican John Koster and County Council Chairman Brian Sullivan, a Democrat.
Council members also have been questioning Reardon's job performance. They sent Reardon a letter asking why he had signed just a quarter of the 89 county ordinances sent to him for signature over the past year. Haakenson's signature appears on 66 of those ordinances, while Reardon's executive director, Peter Camp, signed one.
The letter reminded Reardon that county code requires him to sign legislation whenever he's available, rather than delegating the authority to someone else in his office.
"In the event that we receive ordinances signed by someone other than yourself who does not indicate that they are signing as the Acting County Executive, we will assume you are out of the county or are temporarily disabled and trust that your records will support that assumption."
The letter was signed by Sullivan.
The resolution the council approved Wednesday says information about Reardon that has surfaced as a result of the patrol investigation has become an increasing obstacle to running county government. It mentions allegations of misappropriation of county money and violations of state campaign law.
The resolution goes on to say that newspaper and television coverage has provided detailed descriptions of "county resources being used for Executive Reardon's political campaign and to facilitate a personal relationship with a county employee."
The Herald published evidence last week that Reardon repeatedly used taxpayer resources to raise money for his re-election and to communicate with campaign staff. Meanwhile, The Seattle Times and its television news partner, KING-TV, featured interviews with the female county employee who claimed a long-running affair with the county executive -- a liaison she alleged was pursued on county time and using county funds.
Reardon, 41, has been under investigation by state troopers since October. Word of the probe surfaced Nov. 3, less than a week before the general election, which saw him win a third term in office.
Politically, Wednesday's resolution created an unusual split. The county GOP chairman praised the action of the County Council's Democratic majority, while his Democratic counterpart registered dissent.
"The council did what it thought was necessary, but I completely disagree with that step," said Bill Phillips, chairman of Snohomish County Democrats.
Phillips said he wouldn't prejudge the results of the investigation and would wait for troopers to finish their job.
"For me, we're exactly where we were three months ago," he said. "I'm not going to join a chorus asking Aaron to step down because the investigation is taking too long. That's not his fault."
Snohomish County GOP chairman Bill Cooper said Reardon should have gone on administrative leave long ago.
"I am proud of the County Council, largely Democrat, for taking the action they did. It was the right thing to do," Cooper said. "They're ratifying the position that this is not a partisan, political issue, this is a public trust issue."
The probe of Reardon began after county human services employee Tamara Dutton went to Somers' office to report that she had traveled with the county executive, who is married, on out-of-town county business as part of a long-running affair. Dutton alleged that Reardon did little work during those trips. She and Reardon have known each other since attending Mariner High School in the 1980s.
Somers brought Dutton's allegations to county attorneys, who referred the investigation to state troopers to avoid a conflict of interest.
Dutton has claimed that she also met with the executive locally during regular business hours as part of the affair.
Reardon repeatedly has declined to discuss his connection to Dutton. He's denied wrongdoing.
Some of the evidence being reviewed by detectives has been made public under state records laws.
The documents point to possible misconduct.
The bills for Reardon's county-issued cellphone show lengthy conversations with Dutton.
Those same phone bills, emails and Reardon's official schedule also show that he made regular use of county resources for his successful re-election bid. An analysis by The Herald turned up evidence that Reardon repeatedly made fundraising calls during periods when his work schedule indicated he was engaged in "staff meetings." Campaign finance records and interviews confirmed that Reardon was calling people and organizations for money.
That activity constitutes a potential violation of state campaign-finance laws, which could result in steep fines. County rules also prohibit using taxpayer-funded resources such as phones and offices for campaigning or political fundraising.
Reardon has made few public appearances since election night on Nov. 8, though he did attend President Barack Obama's speech at Boeing's Everett facility on Friday. He was not among the government leaders who greeted the president on the tarmac after Air Force One landed at Paine Field, the county-operated airport.
The State Patrol has declined to estimate how long the investigation could take.
At Wednesday's hearing, representatives of the union that represents most county employees and the union local that represents Paine Field firefighters spoke in Reardon's favor. Both groups supported Reardon's re-election.
Noah Haglund: 425-339-3465, firstname.lastname@example.org.
More Local News Headlines
When he saw his neighbor’s home on fire, Kaiden, 17, didn’t hesitate Edmonds hires firm to tackle downtown traffic snarl Family holds vigil for man who died in Island County Jail Front Porch: Fire districts open houses 2 arrested in fatal shooting of teen near Lynnwood Judge says molestation trial of former police sergeant can proceed Copper-wire theft knocks out power near Cathcart Police in Mountlake Terrace seek stabbing suspect
Our new comment system is not supported in IE 7. Please upgrade your browser here.