A state senator seeking a seat on the Public Utilities Regulatory Authority accused agency leaders of attempting to tarnish his reputation by levying more than $1 million in fines against his company, according to a letter his attorney sent to the governor, legislative leaders and members of the media Sunday.

The letter also alleges that state Sen. John Fonfara, D-Hartford, has been the target of a smear campaign regarding his former company, Wattifi Inc., ever since Gov. Ned Lamont announced plans last month to nominate the senator to one of two vacant seat’s on PURA’s board.

“The campaign to discredit Wattifi — and, by association, Senator Fonfara — seems very likely calculated to impugn his reputation by those seeking to prevent his appointment to PURA,” Fonfara’s attorney, R. Bartley Halloran, wrote, referencing news reports first published by CT Insider that Fonfara’s company had racked up penalties.

“The alleged penalties referenced in these news reports were groundless and improperly ordered — reflecting the very same unlawful PURA practices that have rightly received much scrutiny in recent months,” he added. “Perhaps worse, these penalties appear to have been ordered in direct retaliation for Senator Fonfara voicing concerns about legislation that would have unwisely aggrandized the authority of PURA’s chairperson.”

The chairperson is Marissa Gillett, whose pending reappointment to another four-year term at PURA kicked off the sequence of events that eventually led to Lamont announcing a plan for Fonfara join her at the agency.

The legislature’s Executive and Legislative Nominations Committee was considering Gillett’s nomination last month, but several members of the committee — including Fonfara — had expressed reservations over her tenure. On the morning of a planned vote on the nomination, Lamont announced he’d reached a deal that would advance Gillett’s reappointment, make PURA a quasi-public agency and appoint Fonfara and former state Rep. Holly Cheeseman, R-East Lyme, to two vacant seats on the board.

After the deal was announced, Fonfara voted with other Democrats to advance Gillett’s nomination.

But in his letter Sunday, Fonfara’s attorney accused Gillett of violating state law and the agency’s rules by issuing unilateral decisions against the senator’s business and attempting to “thwart judicial review” by placing matters before the board in uncontested dockets.

Similar allegations are at the center of a lawsuit filed earlier this year by the state’s two largest utility companies, Eversource and United Illuminating, accusing Gillett of usurping the authority of her fellow commissioners.

“As has been extensively detailed in legal filings and elsewhere, PURA must act through the votes of a panel of commissioners but, instead, Chair Gillett has issued thousands of unilateral rulings over the Executive Secretary’s signature without recorded votes and without disclosing the true authorship of these rulings,” the letter read.

Fonfara did not respond for requests for comment Monday to explain why he voted in favor of Gillett in spite of the concerns outlined by his attorney.

Theresa Govert, PURA’s chief of staff, said Monday that the agency had not been contacted by either Fonfara or his attorney regarding the the fines owed by Wattifi — other than a public records request filed by Halloran on March 14.

Govert declined to comment on the contents of Halloran’s letter.

Fonfara founded Wattifi in 2018 as a supplier operating on Connecticut’s deregulated electricity marketplace. The company attempted to offer a flexible, hourly-rate structure for its customers rather than the traditional, fixed-rate pricing model used by other suppliers.

Beginning that same year, PURA instructed the state’s electric utilities to come up with a redesigned billing format that displays information about the competitive supply market, with a portion of the cost for that process to be shared by the third-party suppliers. By the time PURA came to collect those costs several years later, however, Wattifi was in the process of closing its operations, according to Fonfara’s own recounting of those events as well as Halloran’s letter.

Fonfara has since argued that his company should not have been assessed the costs of the redesign, which totaled $57,168, because he never used the new system. However, PURA alleges that Fonfara never responded to the agency’s order to pay those costs or $5,000-a-day late fees that eventually ballooned to over $1 million. (PURA offered to waive the daily fines if Fonfara or Wattifi paid the original amount within 20 days of the agency’s notice on December 7, 2023).

A few months before PURA first assessed Wattifi for the costs of the bill redesign, Fonfara spoke out against a provision within a larger energy bill that would have allowed PURA’s chair to choose when to become the arbiter of certain decisions before the agency.

While that provision was ultimately removed the bill, which Fonfara voted in favor of, Halloran said in his letter that both he and the senator believe the comments sparked PURA to retaliate against Wattifi.

Halloran did not respond to a request for comment on Monday.

When asked about the letter during a press event Monday, Lamont said he had no plans to back off of the deal to appoint Fonfara, though he has in the past said that the senator’s conflicts with regulators pose “a problem” for his desire to serve on PURA.

“Certainly, the Democratic leaders think he’s the best person for the job,” Lamont said. “There’s no plans to change that.”

Later, his office released a statement standing by PURA in its handling of Wattifi and other cases.

“We’re in receipt of Mr. Halloran’s letter and while he has a right to express his opinions on behalf of his client, this is a closed matter that was before PURA years ago,” Lamont spokesman Rob Blanchard said in the statement. “As for claims about PURA’s conduct, they have acted in a matter that is consistent with the law and within their purview, as evidenced by the courts repeatedly upholding their decisions.”

Halloran’s letter was also sent to Republican and Democratic leaders in the General Assembly, along with members of their staffs.

House Minority Leader Vincent Candelora, R-North Branford, said Monday that he has requested Gillett turn over documents related to PURA’s handling of the Wattifi case as well as the agency’s general decision-making procedures. While Candelora said he is reserving judgment on the allegations made against Fonfara for now, he criticized the process that led to the senator’s nomination last month.

“All of this should have been vetted behind closed doors,” Candelora said. “It’s a misstep by the governor’s office, PURA and everyone involved.”

House Speaker Matt Ritter, D-Hartford, said Monday that the letter has not disrupted plans to take up Gillett’s nomination when the House convenes for its floor session next Wednesday. If approved by the House, her nomination will face one final vote before the Senate.

Reporters Andrew Brown, Mark Pazniokas and Jessika Harkay contributed to this article.