The web is in a "downward plunge to a dysfunctional future", its inventor, Sir Tim Berners-Lee, has warned.

In an interview with the BBC to mark 30 years since he submitted his proposal for the World Wide Web, Sir Tim called for global action to tackle its problems.

Despite growing concerns surrounding personal data, privacy and hacking, Sir Tim said its issue can be addressed, acknowledging that many people now doubt that the internet can be a force for good.

Sir Tim told the BBC: "I'm very concerned about nastiness and misinformation spreading."

"When the Cambridge Analytica thing went down [people] realised that elections had been manipulated using data that they contributed," he added.

In an open letter, Sir Tim said there were three key areas of "dysfunction" for the world to tackle. The first is hacking and harassment, while he also highlighted system designs and business models that reward clickbait. Finally, Sir Tim warned against the unintended consequences of aggressive or polarised discussions.

However, these issues can only be tackled with the contribution of all society, Sir Tim stressed, including members of the public, business and political leaders.

He said: "We need open web champions within government - civil servants and elected officials who will take action when private sector interests threaten the public good and who will stand up to protect the open web."