With the FBI escalating its scrutiny of labor leader John J. Dougherty and his politically powerful electricians' union in a new raid on its Philadelphia headquarters last week, the embattled union chief is dismissing the latest move by federal agents as an “abuse of power” and has sought to link it — without evidence — to his union’s support of Joe Biden’s presidential campaign.

In a letter sent Sunday to members of Local 98 of the International Brotherhood of the Electrical Workers — two days after agents arrived with search warrants at the union’s offices on Spring Garden Street — Dougherty questioned the timing of the raid, coming within weeks of the presidential election and shortly after its endorsement of Biden.

He also suggested that agents purposefully moved one of Local 98′s old campaign posters for Hillary Clinton and left it on the desk of a union official while conducting their search in an attempt to send a message.

“What message was that stunt meant to deliver?” he asked in the missive. “That Local 98′s support of Democratic presidential candidates have legal repercussions?”

The FBI and the U.S. Attorney’s Office declined to respond Tuesday to Dougherty’s claims.

The letter is only the latest attempt by the union chief, known widely by his nickname, “Johnny Doc,” to dismiss the federal case against him as an attack on his union and its considerable political fund-raising and organizing work.

The strategy appears aimed to shore up support among Dougherty’s union members, but those arguments are unlikely to help him in court as he faces trial next year on federal charges of bribery and embezzlement of union funds.

The indictment filed against Dougherty and six members of his inner circle last year makes no mention of Local 98′s broader work in electoral campaigns outside of his support for Philadelphia City Councilmember Bobby Henon, whom Dougherty is accused of bribing with a no-show union job.

Dougherty’s lawyers have refrained, thus far, from making any accusations of electoral interference in court — a move that could be dismissed by a judge for what is known as “jury nullification,” or an effort to persuade a jury to decide a case based on factors outside of the allegations and evidence presented in court.

According to sources who have reviewed the search warrants served Friday, the focus of the FBI’s latest probe has no ties to the union’s election work, either.

It appears to be primarily focused on alleged threats of violence made to dissident union members who questioned Dougherty’s leadership in the wake of his January 2019 indictment, the sources said.

Nevertheless, in the Sunday letter — Dougherty’s first remarks on the raid — he insinuated that agents involved in the search participated in a wide array of misconduct, suggesting without evidence that they had tipped off the media and spread misinformation that the home of another Local 98 member, a Democratic ward leader, had been searched.

He seized on the optics of the FBI’s first search of the headquarters in August 2016 — during which agents spent hours carting boxes out of the building underneath a massive banner members had hung in support of Hillary Clinton — and noted that their return to the building Friday came just days after the union had hung a new Biden banner in the same place.

Dougherty also asserted that all of the information agents seized last week — including cell phones from him and several other union members — was already in their possession after the raid four years earlier.

“I’m pissed off and you should be, as well,” Dougherty wrote. “I have been under federal scrutiny for over 28 years and I never once failed to respond to a subpoena or a demand for information. … Friday’s raid was utterly unnecessary. It was another despicable attempt to try me and this union in the court of public opinion.”

Only briefly did Dougherty acknowledge dissent within Local 98′s ranks as a possible source of the FBI’s renewed scrutiny; he dismissed the perceived disloyalty as “disturbing” and “a damn shame.”

The warrants used to search the property Friday sought information on, among other things, union dealings with a website, the truthaboutyourlocal.com, which was anonymously launched by a Local 98 member in the months after Dougherty’s indictment as a collection of news stories and disparaging comments about the labor leader and his inner circle.

This summer, Local 98 filed a defamation lawsuit against Local 98 member Charles Battle, who was considering a run against Dougherty for a union leadership post, alleging he and his wife were running the site.

It was abruptly taken down after the filing of the suit. However, the website reappeared over the weekend with an altered URL in the wake of Friday’s raid.

Since charging Dougherty last year, federal prosecutors have gone out of their way to characterize their case as a prosecution of a union leader they accuse of enriching himself and his family on the backs of union members and not an attack on the union itself.

In court they have accused him and his codefendants of embezzling more than $600,000 in union funds from Local 98′s coffers, much of which they spent on mundane household goods, travel, and home repairs.

Prosecutors also allege that Dougherty bought Henon’s Council vote on issues key to the union and his personal interests.

Both Dougherty and the councilman have repeatedly denied wrongdoing and argued that Henon’s union salary couldn’t be a bribe, given he had held the job for years before his rise to elected office. They have vowed to fight the case at a trial scheduled for January.

In the meantime, Dougherty assured Local 98′s members in his letter Sunday, he is refusing to be cowed by the threat of possible conviction and prison time and touted his recent accomplishments in securing raises and money-saving health-care contracts for his members even amid the pandemic.

“The message to everyone is simple,” he wrote. “It’s business as usual at IBEW Local 98. We don’t blink.”