Sir Nick Clegg has been asked to appear before a committee of MPs investigating the online abuse and harassment of MPs.

The former deputy prime minister is now Facebook's head of global affairs.

Labour MP Harriet Harman, chairwoman of the Joint Committee on Human Rights, said he was "uniquely well placed" to give evidence on whether social media abuse was stifling democracy.

Sir Nick's boss, Facebook founder Mark Zuckerberg, has turned down repeated requests to appear before MPs.

Facebook, which also owns WhatsApp and Instagram, has been accused along with other social media giants of not doing enough to tackle threats against MPs and other elected officials on its platforms.

The company has launched tools to increase the transparency of political advertising, which is largely unregulated online.

Sir Nick, who was hired by Facebook in October last year, has conceded the company needs to do more.

In a letter to the former Lib Dem leader, Harriet Harman said: "I am writing to invite you to give evidence because JCHR members have heard evidence from MPs about the high level of abuse, threats and intimidation and the extent to which social media is a significant driver of this.

"As someone who has yourself been an MP, and is now head of global affairs at Facebook, you are uniquely well placed to give evidence on this."

Ms Harman said she wanted Sir Nick to give evidence to the committee, which is conducting an inquiry into democracy and free speech, in "early March".

The committee's inquiry was looking at "freedom of association focusing on the balance between the right to protest and the right of MPs to be able to go about their work safely and free from threat and harassment", she added.

Mark Zuckerberg has come under fire from the chairman of another UK Parliamentary committee, Damian Collins, after repeatedly turning down requests to be quizzed on fake news and data privacy.