Stephen O. Simpson served as Loudoun County’s sheriff from 1996 to 2012. (Dominic Bracco II/For The Washington Post)

Former Loudoun County sheriff Stephen O. Simpson plans to run as an independent candidate in the race for county sheriff, according to local reports — a development that quickly drew condemnation from the county Republican committee.

Simpson, who was Loudoun’s sheriff from 1996 to 2012, was unseated in the November 2011 election by current Sheriff Michael L. Chapman, a former Drug Enforcement Administration agent who campaigned aggressively on promises to improve the efficiency and professional reputation of the sheriff’s office.

Nearly four years later, Simpson said that morale at the sheriff’s office has reached an “all-time low” since he left and that many of the sheriff’s office employees have urged him to run, according to a May 11 post on a local conservative blog, the Bull Elephant.

“Yes, I am considering a run for office after an outpouring of people asking (nearly begging) me to do so,” Simpson said, according to the blog. “[Sheriff’s office employees] tell me they cannot face another 4 years under the current Sheriff.”

The former sheriff also claimed that he has the support of Democrats who are less than enthusiastic about Democratic nominee Brian Allman, according to the blog post.

Simpson later confirmed to the Loudoun Times-Mirror that he planned to enter the race and that he was circulating a petition to gather the necessary signatures.

His remarks did not please Loudoun Republican Committee Chairman Mike Haynes, who called on Simpson to support Chapman, the Republican nominee.

“For the past few months, Steve Simpson has been frequenting Loudoun Republican meetings, attending fundraisers and events, and apparently trying to be part of the Republican Party again,” Haynes said in a statement Tuesday. “For him to now be considering a run as an independent is very unfortunate and unacceptable.”

Haynes added that “part of the reason” Simpson lost the election to Chapman was because Simpson had previously run as an independent after losing the Republican primary.

“Being a Republican has to mean something, and you can’t jump in and out of the party to further your political career,” Haynes said.

The committee chairman added that Simpson is “more than welcome” in the Republican party if he honors a pledge to support the party’s nominees.

Simpson participated in a Republican committee convention this month, during which Chapman narrowly defeated primary challenger Eric Noble, a former major with the sheriff’s office. The contest between the two Republican candidates had become heated in the weeks before the primary.

By voting as a Republican delegate, Haynes claimed, Simpson had promised to support the eventual Republican nominee. If he opts instead to run as an independent, Haynes said, “we will make every effort to defeat him in November, just as we will the Democrat in the race.”

Simpson, who declined a request for comment from The Washington Post, previously told Leesburg Today that Haynes’s statement was “in poor taste,” adding that he had received “huge” support for his petition to join the election as an independent.

Chapman told The Post that he looks forward to sharing his “record of accomplishment and plans for the future” with Loudoun voters as the campaign progresses.

“Steve Simpson was overwhelmingly rejected by Loudoun voters four years ago,” Chapman said. “His approach to law enforcement was discredited as lazy, inefficient, and as failing to anticipate emerging threats of terrorism, drugs, online safety and more.”

Allman, a former Fairfax police detective and the Democratic nominee for sheriff, has also been a subject of recent controversy after an incident at a Loudoun Democratic Committee meeting May 8. Democratic officials said Allman was asked to leave after he confronted committee member Larry Roeder, who had raised concerns about Allman’s potential membership with the committee. Allman later filed a defamation complaint against Roeder in Loudoun County Circuit Court.

Allman told The Post that he welcomes “the addition of former sheriff Simpson into the race” and believes the county’s top law enforcement agency should be a police department rather than a sheriff’s office led by an elected official.

“I am the only entrant in the sheriff’s race that supports this proposal,” he said.

According to local reports, Simpson has said that he plans to make a formal campaign announcement in the coming days.