Attorneys for Julian Assange on Wednesday filed a legal challenge that aims to block extradition and force the Trump administration to unseal secret charges against the WikiLeaks founder that were accidentally revealed to the public in November.

"U.S. federal prosecutors have in the last few months formally approached people in the United States, Germany, and Iceland and pressed them to testify against Mr. Assange in return for immunity from prosecution."
—Defend Assange Campaign

Assange has been living as a political asylee at the Ecuadorian Embassy in London since 2012 to avoid being extradited to Sweden—which has dropped its request—or the United States, where he could face prosecution for his work as journalist and publishing classified information.

Reports have circulated since last summer that Ecuador's government has made Assange's stay in the London residence "increasingly inhospitable" and has been in talks with the U.S. government to strike a deal over revoking his asylum protections.

As Ecuador faces pressure from the Trump administration to acquiesce and hand him over, Assange's attorneys are requesting that the Washington, D.C.-based Inter-American Commission of Human Rights (IACHR) urgently intervene to protect him from extradition.

Assange's lawyers on Wednesday filed a 1,172-page application with the IACHR demanding that the U.S. Justice Department cease "espionage activities" against him and unseal the charges, asserting that the U.S. government "is required to provide information as to the criminal charges that are imputed to Mr. Assange in full."

Given, as the filing alleges, that the Trump administration has been ramping up its investigation into Assange, Baltasar Garzón, the international coordinator of his legal team, is also calling for "international solidarity for this case in which the right to access and impart information freely is in jeopardy," according to a statement from the Defend Assange Campaign.

"The submission reveals for the first time that U.S. federal prosecutors have in the last few months formally approached people in the United States, Germany, and Iceland and pressed them to testify against Mr. Assange in return for immunity from prosecution," the statement said. "Those approached are associated with WikiLeaks' joint publications with other media about U.S. diplomacy, Guantanamo Bay, and the wars in Iraq and Afghanistan."

In a tweet that linked to a report about the filing, The Intercept's Glenn Greenwald decried the lack of "uproar" among reporters—"the people whose profession is also to publish and reveal secrets"—over the Trump administration's refusal to reveal the charges against Assange.

Among those who have spoken out is the Reporters Committee for Freedom of the Press, which is also fighting to have the charges unsealed.

The group's legal director, Katie Townsend, told NBC News, "Whether the charges against Mr. Assange are made public by the district court in response to the Reporters Committee's motion, or whether they are made public as a result of separate actions being taken by Mr. Assange on his own behalf, we think the public will benefit from knowing what those charges are."