Social media is acting like an "echo chamber" and polarising political debate, says entrepreneur and former senior adviser to David Cameron Rohan Silva.

His comments follow Mark Zuckerberg's commitment to tackle fake news on Facebook, which he denied had aided Donald Trump's presidential election victory.

"The genuinely worrying aspect of social media is the way it's driving the polarisation of the debate by serving up content that you already like, already agree with, rather than things that you might occasionally disagree with," Mr Silva said.

(Image: Facebook. Credit: Getty Images)