David Cameron has openly criticised Donald Trump, saying that the US president is "undermining democracy" with his "fake news" attacks on media outlets.

The former British prime minister said that Trump's actions served to help Russian president, Vladimir Putin, by deflecting scrutiny away from Moscow spreading anti-western propaganda.

In his first public address since leaving office, Cameron told a conference organised by Transparency International that the use of the term "fake news" was "not just a questionable political tactic. It's actually dangerous".

"President Trump, fake news is not broadcasters criticising you, it's Russian bots and trolls targeting your democracy, pumping out untrue stories day after day, night after night.

"When you misappropriate the term fake news, you are deflecting attention from real abuses. Ignoring what's happening on social media is facilitating a form of corruption that is undermining democracy," he told the London audience.

Cameron also raised question marks over how Russia won the right to stage the 2018 World Cup, telling the audience: "President Putin actually boycotted the whole thing because he said it was riddled with corruption. He was right – it was.

"I am sure he wasn't completely surprised when Russia actually won the bid. You couldn't make it up. In the years since, 10 of the 22 members of that Fifa executive committee were indicted or punished."

Cameron also said that the EU "has been far too slow" to counter Russian propaganda and interference in its democracies.

"Barack Obama used to challenge European leaders over how we seemed to ignore or even tolerate Russian subversion of some eastern European business, energy, media or even political interests. He was bang on target," he said at the conference, according to the Times.