Samuel Alito has become the latest Supreme Court justice to face an ethics firestorm, adding to a stream of controversies at the high court about luxury trips and recusals.

Alito on Tuesday night took the rare step of penning a Wall Street Journal opinion piece to rebut a ProPublica story, published hours later, that detailed an undisclosed Alaskan fishing trip Alito took in 2008.

The conservative justice admitted that he accepted a seat on the private plane paid for by billionaire hedge fund owner Paul Singer, a major Republican donor, and later participated in several cases in which a subsidiary of Singer’s fund was a party.

But Alito denied any wrongdoing, clashing with judicial watchdog groups who say the revelation has only added to a string of ethical lapses by Justice Clarence Thomas and others at the Supreme Court.

Senate Judiciary Committee Chairman Dick Durbin (D-Ill.) and Sen. Sheldon Whitehouse (D-R.I.) responded by vowing to mark up Supreme Court ethics legislation following Congress’s July Fourth recess.

“Justice Alito’s response to this latest reporting shows exactly why this Supreme Court urgently needs an ethics overhaul to hold the justices accountable for the many instances of ethical wrongdoings that continue to come to light,” Whitehouse said in a statement.

Democrats renewed a push for the Supreme Court to adopt a binding code of ethics earlier this year, when Thomas came under fire for undisclosed luxury trips he took at the expense of Harlan Crow, a GOP megadonor and real estate developer. Thomas also denied wrongdoing.

Now Alito is caught in the crosshairs.

ProPublica reported that Leonard Leo, who led a years-long push to move the court to the right and aided Alito and other conservative nominees in their confirmation battles, helped organize the 2008 Alaskan fishing trip. 

Leo reportedly invited Singer and asked if he and Alito could fly on the hedge fund manager’s jet. Alito conceded that he accepted the flight and then stayed for three nights at the Grand Salmon Lodge, paid for by the lodge’s owner, Robin Arkley II. Arkley and Singer were both major donors to Leo’s political groups, according to ProPublica. 

“One day it’s ‘my superyacht trips funded by a GOP megadonor were ethical because we’re such close friends,’ and the next it’s ‘my luxury fishing vacation funded by a GOP megadonor was ethical because I barely knew the guy,” Sarah Lipton-Lubet, president of Take Back the Court Action Fund, said in a statement.

Unlike Thomas, who publicly addressed his controversy a day after it became public, Alito took the unusual step of preempting ProPublica’s story with his article in the Journal, titled “ProPublica Misleads Its Readers.” Alito said ProPublica had reached him for comment on the story, making him aware that it was preparing to publish the piece.

Gabe Roth, executive director of watchdog group Fix the Court, in a statement said the strategy had a few positives.

“First, you don’t see Supreme Court justices writing op-eds all that often, right?” he said. “Politicians write them fairly frequently, of course, but the thing is, the justices have been acting like politicians since the start of the Republic, even more so in recent years, so Alito’s missive might help more Americans finally realize this.”

Like Thomas, Alito said he believed the trip fell under a personal hospitality exception to financial disclosure rules. The exception was clarified earlier this year to explicitly note that it doesn’t apply to transportation and stays at commercial properties.

Alito said his plane seat would’ve been vacant if he declined.

“It was my understanding that this would not impose any extra cost on Mr. Singer. Had I taken commercial flights, that would have imposed a substantial cost and inconvenience on the deputy U.S. Marshals who would have been required for security reasons to assist me,” Alito wrote.

Singer’s hedge fund and the Supreme Court’s public information office did not return a request for comment. A lodge employee said the trip happened several years before the current owner purchased the property and that they had no further details about the trip.

In a statement to ProPublica, Singer’s spokesperson said the billionaire “never discussed his business interests” with Alito and that his companies did not have “any pending matters before the Supreme Court, nor could Mr. Singer have anticipated in 2008 that a subsequent matter would arise that would merit Supreme Court review.”

At the time of the trip, a subsidiary of Singer’s hedge fund, NML Capital, was in the midst of a years-long court battle to collect on Argentinian debts it purchased at steep discounts during an economic crisis there. After Argentina defaulted in 2001, NML refused to participate in debt restructuring proposals, instead suing in court to maximize returns.

One year before the trip, NML and another entity petitioned the Supreme Court to review a lower ruling issued as part of the battle. 

A review of the court’s docket shows that, between 2009 and 2014, NML was a party in seven requests for the court to review various aspects of the battle, at times asking the justices to let lower rulings stand while other times asking them to intervene. 

The justices declined to hear all but one of those cases. In each instance, as is typical, the justices did not make their votes public, so how Alito voted remains unclear. NML also submitted two amicus briefs supporting other Supreme Court disputes.

In the case they did hear, the Supreme Court handed down a 7-1 ruling in favor of NML, allowing it to search for additional Argentinian assets by rejecting the country’s immunity arguments. Alito joined the majority opinion.

Singer’s involvement was detailed in various media reports about the case, including in The Wall Street Journal. In his op-ed in the same publication, Alito claimed he was unaware of the billionaire’s connection to the case, and he pointed out Singer’s name did not appear in any of the written briefs.

“It would be utterly impossible for my staff or any other Supreme Court employees to search filings with the SEC or other government bodies to find the names of all individuals with a financial interest in every such entity named as a party in the thousands of cases that are brought to us each year,” Alito wrote.

Singer’s hedge fund, Elliott Management, is a party in a pending, unrelated case at the Supreme Court. The fund has asked the justices to stay out of the dispute.

The justices are set to discuss whether to do so at a closed-door conference in September.