BBC director-general Lord Tony Hall has said the world is in the grip of the biggest attack on truth since the 1930s.
The broadcasting boss has compared the current prevalence of fake news as similar to the misinformation and propaganda in the decade which saw the rise of Adolf Hitler.
Speaking at the Global Conference For Media Freedom in London, Lord Hall said: “An assault on truth is an assault on democracy.
“We are now in the midst of the biggest assault on truth, in my view, since the 1930s.
“All those who believe in integrity in news must work together to turn the tide.”
Lord Hall compared the current media environment to the period which saw the rise of fascist regimes in Europe, and the excesses of Joseph Stalin’s communist dictatorship.
He added that the BBC had a role to play in battling fake news and press repression across the world.
Lord Hall said: “We need to reassert the core principles of good journalism like never before.
“In a sea of disinformation and partisan reporting, we need to stand up for independence, impartiality, and reporting without fear or favour.”
He added: “I’m determined that we use that unique reach and trusted voice to lead the way – to create a global alliance for integrity in news.
“We’re ready to do even more to help promote freedom and democracy worldwide. We want to play our part to the full at the heart of this critical campaign.”
Lord Hall shared a stage with speakers including Jeremy Hunt and Amal Clooney at the London conference.