The Justice Department fretted about the "possible bias" of a source being used in a FISA application to obtain warrants against Trump campaign associate Carter Page, but the FBI pushed ahead anyway, text messages show.

Christopher Steele, the former British spy and author of the so-called Trump dossier, appears to be the source being referred to. He was being paid by Fusion GPS, which was itself being funded by the Clinton campaign and the Democratic National Committee through the Perkins Coie law firm, after initial financing from Republican opponents of Trump. Steele is the only known confidential source to have been cited in the FISA application.

The text messages, between then-Deputy Director of the FBI Andrew McCabe, who was later fired, and former FBI attorney Lisa Page — who was having an affair with FBI agent Peter Strzok — were obtained by Fox News.

They reveal that Stuart Evans, deputy assistant attorney general of DOJ's National Security Division at the time, had "continued concerns" about the "possible bias" of a source being used in the FISA application but that Lisa Page had a sense of urgency about the FISA application being submitted quickly and was considering ending "the hold up" with "a high-level push."

"OI [Office of Intelligence] now has a robust explanation re any possible bias of the chs [Confidential Human Source] in the package," Page texted McCabe on Oct. 12, 2016. "Don’t know what the holdup is now, other than Stu’s continued concerns. Strong operational need to have in place before Monday if at all possible, which means to ct tomorrow. I communication you and boss’s green light to Sty earlier, and just sent an email to Stu asking where things stood. This might take a high-level push. Will keep you posted.”

Page said she would press the issue with Evans by "invoking" McCabe's name. Further texts show that a meeting would eventually be set up including then-Deputy Attorney General Sally Yates at the direction of the White House. The FISA application, relaying heavily on Steele's dossier, would be submitted to the Foreign Intelligence Surveillance Court just days later.

Then-Director of the FBI James Comey ultimately signed off on the application to the Foreign Intelligence Surveillance Court for approval to surveil Carter Page. It was dated nine days after the Page-McCabe texts: Oct. 21 2016.

The specific funding of Steele's dossier was never mentioned to the FISA court, either during that first application or during three subsequent FISA renewals. Steele’s anti-Trump fervor and determination to provide his dossier to the media and members of the U.S. government later became well known.

The FBI eventually cut Steele off as a confidential source because he disclosed his relationship with the bureau to the media, but it continued to use his dossier in FISA renewals.

FISA documents named Carter Page as "an agent of a foreign power" — namely Russia — and stated that "the FBI believes Page has been the subject of targeted recruitment by the Russian Government." The FBI tied this to Russia's efforts to "undermine and influence the outcome of the 2016 U.S. presidential election in violation of U.S. Criminal law."

Carter Page has not been charged with any crimes by special counsel Robert Mueller’s office, and he announced earlier Friday that he is cooperating with the House Judiciary Committee in its broad investigation into President Trump.

[Related: Roger Stone pleading the Fifth, won't cooperate with House Judiciary Committee]

Text messages from Lisa Page and FBI lawyer Peter Strzok seemed to reveal anti-Trump bias, and resulted in Strzok being removed from Mueller's team. These texts were also a focus of a DOJ Inspector General report into the handling of the Clinton email investigation.

DOJ Inspector General Michael Horowitz confirmed Thursday that his investigation into possible FISA abuse at the DOJ and FBI is still active.