Labour MPs were paid up to £10,000 for secret meetings with Cold War spies, a former agent has claimed as he revealed they threw him a “farewell party” when he was kicked out of Britain.

Jan Sarkocy, a Czech spy based in London in the 1980s, says he was in contact with 15 of the party’s representatives including Jeremy Corbyn and Ken Livingstone, while John McDonnell was regularly meeting a KGB agent. The claims have been vigorously denied and Mr Corbyn has labelled him a “fantasist”.

He has now claimed that those in Parliament who acted as informants to his secret service – the Statni Bezpecnost or StB – were paid between £1,000 and £10,000.

He said that the payments were made in “cash on an irregular basis”, often at secret meetings in Camden, and could be to cover just a couple of meetings.

But some of the MPs got greedy, he said, adding: “It was big money. Some Labour MPs were asking more and more money, they wanted it.”