Hardly a revelation to anyone who has bothered to fact check the cable news network but coming from an insider this is heady stuff, and apparently Roger Ailes hasn’t figured out who the stool pigeon is.

…a former Fox News employee who recently agreed to talk with Media Matters confirmed what critics have been saying for years about Murdoch’s cable channel. Namely, that Fox News is run as a purely partisan operation, virtually every news story is actively spun by the staff, its primary goal is to prop up Republicans and knock down Democrats, and that staffers at Fox News routinely operate without the slightest regard for fairness or fact checking.

“It is their M.O. to undermine the administration and to undermine Democrats,” says the source. “They’re a propaganda outfit but they call themselves news.”

And that’s the word from inside Fox News.

Note the story here isn’t that Fox News leans right. Everyone knows the channel pushes a conservative-friendly version of the news. Everyone who’s been paying attention has known that since the channel’s inception more than a decade ago. The real story, and the real danger posed by the cable outlet, is that over time Fox News stopped simply leaning to the right and instead became an open and active political player, sort of one-part character assassin and one-part propagandist, depending on which party was in power. And that the operation thrives on fabrications and falsehoods.

“They say one thing and do another. They insist on maintaining this charade, this façade, that they’re balanced or that they’re not right-wing extreme propagandist,” says the source. But it’s all a well-orchestrated lie, according this former insider. It’s a lie that permeates the entire Fox News culture and one that staffers and producers have to learn quickly in order to survive professionally.

“You have to work there for a while to understand the nods and the winks,” says the source. “And God help you if you don’t because sooner or later you’re going to get burned.”

…The former insider admits to being perplexed in late 2009 when the Obama White House called out Murdoch’s operation as not being a legitimate new source, only to have major Beltway media players rush to the aid of Fox News and admonish the White House for daring to criticize the cable channel.

“That blew me away,” says the source, who stresses the White House’s critique of Fox News “happens to be true.”