British Labour leader Jeremy Corbyn has launched a fierce attack on "billionaire press barons" over claims that he held meetings with a Communist spy during the Cold War.

The Labour leader gave his strongest denial yet since the allegations were reported by some newspapers, branding them "increasingly wild and entirely false."

He said while "it's easy to laugh" at the reports, "something more serious is happening."

Mr Corbyn described the claims as "smears" which demonstrate "just how worried the media bosses are by the prospect of a Labour government."

He added: "In the last few days, The Sun, The Mail, The Telegraph and The Express have all gone a little bit James Bond.

"They've found a former Czechoslovakian spy whose claims are increasingly wild and entirely false.

"He seems to believe I kept him informed about what Margaret Thatcher had for breakfast and says he was responsible for either Live Aid or the Mandela Concert, or maybe both."

The message came in a video on social media, after Mr Corbyn criticised a Daily Mail journalist for asking about his contact with a Czech spy in the 1980s.

He said in the post on Tuesday: "The General Election showed the media barons are losing their influence and social media means their bad old habits are becoming less and less relevant.

"But instead of learning these lessons they're continuing to resort to lies and smears. Their readers - you, all of us - deserve so much better.

"Well, we've got news for them: change is coming."

Czech agent

The Sun last week published details of documents from Czech intelligence archives which it said showed the Labour leader had met with a Czech agent named Jan Sarkocy three times.

The newspaper's report said he was given the codename "Cob."

While Mr Corbyn's office acknowledged that he had met a Czech diplomat for tea in the Commons, they said any claim he was "an agent, asset or informer for any intelligence agency is entirely false and a ridiculous smear."

On Monday, the Labour leader threatened to take legal action against a Conservative MP who claimed Mr Corbyn sold British secrets to "Communist spies."

A spokesman for Mr Corbyn said he had instructed solicitors to tell Mansfield MP Ben Bradley to remove the "libellous" tweet or face legal action.