Glenn R. Simpson, co-founder of the research firm Fusion GPS, arrives for an appearance during a House Intelligence Committee hearing in November. (Pablo Martinez Monsivais/AP)

A federal judge Thursday denied a request by Fusion GPS to block the House Intelligence Committee from demanding bank records of 70 of the private investigative firm's transactions with law firms, journalists and contractors, ruling that the request did not violate the company's First Amendment rights to political speech and association.

In a 26-page opinion, U.S. District Judge Richard Leon of Washington said the data sought by the House GOP-led panel in its investigation into Russian influence in the 2016 election concerned only the firm's business activities, not the substance of its clients' political activities.

"The financial records the Committee seeks show only the name of the payer or the payee, the amount of the payment, and certain identifying information. They do not indicate what the payment was for," Leon wrote.

Fusion GPS said it would appeal the ruling, arguing that the House panel was ranging into private dealings unrelated to the Russia probe or to President Trump and cutting into the heart of the firm's rights to associate anonymously with individuals and organizations conducing political opposition research, including in the U.S. presidential election.

Fusion GPS commissioned a dossier on Trump that was researched by former British intelligence agent Christopher Steele and reported then-candidate Trump's alleged ties to Russia. The dossier included some accurate information, along with false or unverified details .

Republican critics of the investigation by special counsel Robert S. Mueller III into the Trump campaign's links with Russia have accused Fusion GPS of working with Democrats to set the probe in motion.

Fusion GPS founders Glenn R. Simpson and Peter Fritsch this week called those arguments "mendacious conspiracy theories" spun by Trump supporters who were seeking to create distractions from and to punish the firm for exposing Trump's links to Russia.

"Instead of focusing its efforts on Russian meddling in the presidential election, the Committee continues to misuse its investigatory powers to punish and smear Fusion GPS for its role in uncovering troubling ties between Russia and the Trump campaign," the firm's lawyer, Theodore Boutrous Jr., said in a statement. "The Committee is violating Fusion's First Amendment and due process rights, and we will continue our fight to protect those rights."

Fusion GPS was hired in fall 2015 by the Washington Free Beacon, a conservative website funded in part by New York hedge fund operator Paul Singer, to investigate several Republican candidates, including Trump, before winding down in May 2016 as Trump closed in on the nomination.

Fusion GPS was retained that April by a law firm and lawyer representing the Democratic National Committee and presidential candidate Hillary Clinton, after which Steele was hired by the firm.

The dossier — a collection of reports compiled by Steele that began in mid-2016 and continued after the election — cited sources familiar with the inner workings of the Kremlin, who said Russia had obtained compromising information about Trump, including lurid alleged details of his 2013 visit to Moscow for the Miss Universe pageant. The Steele reports also alleged that Russia had been working with Trump associates to help him with the election.

Trump has denied those claims and called subsequent probes by the FBI and Mueller a witch hunt. Officials have said that the FBI has confirmed some of the information in the dossier. Other details, including the most sensational accusations, have not been verified.

U.S. intelligence agencies later released a public assessment, which concluded that Russia intervened in the 2016 election to aid Trump. The FBI has been investigating whether any Trump associates helped the Russians.

The committee has been investigating who paid Fusion GPS, who received the dossier, whether steps were taken to verify its accuracy and whether the FBI relied on it as grounds for its counterintelligence investigation.