A US federal judge will announce later on Thursday whether to grant a restraining order to force the White House to return the press pass of reporter Jim Acosta.
US District Judge Timothy Kelly has heard arguments from lawyers for CNN and the Justice Department.
Acosta has had tense exchanges with President Donald Trump and Press Secretary Sarah Huckabee Sanders.
But the dynamic devolved into a near-shouting match during a combative press conference last week following elections in which Republicans lost control of the House of Representatives.
The White House announced that Acosta's White House pass would be revoked. CNN filed a lawsuit against the Trump administration, calling the revocation "an unabashed attempt to censor the press."
Other organisations, including The Associated Press and Fox News, have also filed amicus briefs in support of CNN.
"Whether the news of the day concerns national security, the economy, or the environment, reporters covering the White House must remain free to ask questions" the law firm Ballard Spahr said in a statement on behalf of the news organisations.
"It is imperative that independent journalists have access to the President and his activities, and that journalists are not barred for arbitrary reasons."
Fox News President Jay Wallace said Secret Service passes for working White House journalists "should never be weaponised."
President Donald Trump's administration contends it has "broad discretion" to regulate press access to the White House as it fends off the legal challenge over the revocation of journalist Jim Acosta's "hard pass."
In a legal filing ahead of a Wednesday hearing on CNN's request for a temporary restraining order to restore Acosta's access, the government argued it "was lawful" to punish Acosta for his behaviour during a contentious Trump press conference last week.
It rejected the idea that Acosta was "otherwise eligible" for White House access.
"The President and his designees in the White House Press Office have exercised their discretion not to engage with him and, by extension, to no longer grant him on-demand access to the White House complex so that he can attempt to interact with the President or White House officials."
Australian Associated Press
