Jeremy Corbyn, pictured here in the 1980s, was part of a group of 15 Labour MPs who provided information to Soviet spies during the Cold War, a former Eastern-bloc agent has claimed

Jeremy Corbyn, John McDonnell and Ken Livingstone were among a group of at least 15 Labour figures who passed information to the Soviet Union, a former Eastern-bloc agent has claimed.

Former Czechoslovak spy Jan Sarkocy said the hard-Left politicians were 'great sources' in the 1980s.

Mr Sarkocy, 64, claims there is 'no question' Mr Corbyn and his Labour colleagues knew he was a spy and said: 'Everything was absolutely clear at the time.'

Mr Livingstone, then a Labour MP, was a 'good boy', the Czech agent told the Sunday Telegraph.

He said he had met 'about '10 or 15' Labour MPs but did not name them.

Labour has dismissed Mr Sarkocy's latest claims, which come after he previously alleged Mr Corbyn was a paid informant of the Czech secret police at the height of the Cold War.

Mr Livingstone last night denied the accusations, saying they were a 'tissue of lies'. He admitted meeting a Russian 'representative' though said nothing happened.

Mr McDonnell, now Labour's shadow chancellor, described the claims as 'ridiculous'.

Labour sources said the claims were 'entirely false' and insisted Mr Mr Sarkocy has 'no credibility at all'.

Former Czechoslovak spy Jan Sarkocy claims Mr Corbyn, as well as John McDonnell (left), Ken Livingstone (right) were 'great sources' in the 1980s

Last week documents showed Ron Brown, the late Scottish Labour MP, was also noted as a contact in Sarkocy's files under the codename 'Bento'.

Speaking from his home in Bratislava, Slovakia, Mr Sarkocy told the Sunday Telegraph he had met Mr Corbyn 'more than ten times' .

He had previously said he recruited the MP, codenamed Cob, in the 1980s.

Mr Corbyn was an 'asset' who knew he was working with the Soviet puppet state, Mr Sarkocy claimed.

Last week it emerged Mr Corbyn had hosted Mr Sarkocy – who was posted to Britain as a diplomat under a fake identity – in the House of Commons.

The Labour leader insisted he had no idea Mr Sarkocy, who was actually working for the Czech secret police and was later expelled from Britain by Margaret Thatcher, was a spy.

Mr Corbyn's aides described the claims as a 'ridiculous smear and entirely false'.

Former Czechoslovak spy Jan Sarkocy said the hard-Left politicians were 'great sources' in the 1980s

Former spy Jan Sarkocy has made fresh allegations against senior Labour figures. He claims Mr Corbyn, Mr McDonnell and Mr Livingstone were all spying for the Russians in the 1980s

But Mr Sarkocy directly challenged Mr Corbyn's account, insisting the MP had known about his role within Statni Bezpecnost (StB) – the Communist era secret police force in the country.

'It was a consensual collaboration,' Mr Sarkocy said. At his home in rural Slovakia, the 64-year-old added: 'He was our asset, he had been recruited. He was getting money from us.'

The former agent said the operation to cultivate Mr Corbyn, who allegedly told him that he 'admired' the Soviet Union, was overseen by officials in Russia.

'Recruitment [of Corbyn] was overlooked and secured by Russians,' he said. 'All the information that we got from him and one other supporting source had been verified and then valued not only here, but in Russia as well … It was like this, when we got a tip on someone we worked together with the Russians.'

Mr Corbyn's aides strongly denied the claims.

Last week secret documents suggested the spy targeted Mr Corbyn in the hope of finding information on MI5 and MI6, as well on America's nuclear regime.

Mr Sarkocy said he would not talk about the information Mr Corbyn discussed because the matter was 'confidential'. But he revealed that the Labour leader had helped him build contacts.

Mr Corbyn has claimed the pair simply had a 'cup of tea' in the Commons.

Mr Corbyn strongly denies Mr Sarkocy's allegations. He claimed the pair simply had a 'cup of tea' in the Commons

Mr McDonnell, now Labour's shadow chancellor, described the claims as 'ridiculous'. Mr Livingstone denied the accusations, saying they were a 'tissue of lies'

However, Mr Sarkocy – who at the time used the alias Lieutenant Jan Dymic – said they met more often than the three times listed in archived records. He said Mr Corbyn was a regular at events within the Czech embassy in Kensington, London, at the time. The ex-spy claimed the then backbench MP was also in touch with other StB agents working from within the agency.

Asked if he met Mr Corbyn on more occasions than documented, he said: 'Yes, of course. It's not important what you can find in official documents. Don't forget, a lot of them were destroyed.'

As well as their two Westminster meetings in 1986 and 1987, and a meeting at Mr Corbyn's constituency office, he claimed that they met in 'intellectual circles'.

'You can't do it openly,' the Slovak national said. 'What was important for us was to be able to move on, get more contact to create a network. He [Corbyn] put us in touch with other people … He knew I was there as a diplomat.

'At that time there was no question about whether you were working for the StB or as a diplomat. It was the same. There was no reason to stress that I was working for the StB because I was working in diplomacy.'

The Labour leader met the Czech agent at least three times after being vetted by communist handlers in 1986, papers reveal

Mr Corbyn allegedly provided the spies with material about the arrest of an East German, according to the leaked documents

Mr Sarkocy, who went on to become a businessman after going back to Slovakia and having a brief return to spying before the fall of the Iron Curtain, added: 'Corbyn admired the Soviet Union at the time … Money wasn't his sole motive.

'These were all highly intellectual and mature people, graduates of universities like Cambridge, Oxford.'

Asked how he tried to establish Mr Corbyn as a contact, he said: 'Well you come and get to talking, you politely ask whether he'd like to co-operate or not, how he sees things. The binding act can be in written form or verbal.'

He added that 'if something happened at the time, he [Corbyn] knew he could go live in Russia', but he denied that any such proposal was discussed with the MP.

Three years after Mr Sarkocy arrived in London posing as a diplomat in the Czech embassy, he was evicted by Mrs Thatcher for his role in a spy ring with three others.

The ex-spy, who was renowned by bosses for his innovative ways of cultivating sources, last week bragged about his ability to work inside the British system.

One page of the documents reveals contact was established with Mr Corbyn twice in 1986

A spokesman for Jeremy Corbyn (pictured in Scotland on Monday) denied the allegations, branding them 'smears'

'I knew what Margaret Thatcher would eat for breakfast, lunch and dinner the next day and what dress she would be wearing,' he said.

Hinting at his proximity to other MPs during his trips to the Commons, he added: 'I was going there for a whisky. There was a really good whisky. It is great to be on the terrace and looking at the River Thames.'

How Corbyn helped two Cuban spies come to UK Jeremy Corbyn faces fresh questions over links to foreign secret agents as it emerged he helped two Cuban spies to Britain. The Labour leader hosted the pair in the Commons in July 2016 despite warnings they were a threat to national security. Rene Gonzalez and Gerardo Hernandez had served jail terms in the US after being convicted of spying for Fidel Castro's government on Cuban exiles. It comes after it was alleged Mr Corbyn was 'groomed' as a contact by a Czechoslovakian spy in the 1980s – a claim which he strongly denies. The Cuban spies were part of the Miami Five, a group arrested in 1998 and found guilty in 2001 of trying to infiltrate US military installations. Gonzalez was released in 2011, while Hernandez was let out in 2014. Mr Corbyn invited Gonzalez to Commons meetings on Cuba-US relations, but he was denied a visa by then home secretary Theresa May on security grounds. MPs led by Mr Corbyn and John McDonnell wrote to the Court of Appeal saying this breached his human rights. Their appeal was upheld. Advertisement

Documents seen by the Daily Mail last week showed Ron Brown, the late Scottish Labour MP, was also noted as a contact in Sarkocy's files under the codename 'Bento'.

At the time, there was significant concern that spies from behind the Iron Curtain were targeting members of the Labour Party for state secrets.

Mr Sarkocy, an engineering graduate, moved to London in May 1986.

Secret documents in an StB archive in Prague revealed Mr Corbyn was vetted as a possible contact by the Czech interior ministry and displayed a 'positive' view of the eastern bloc during meetings.

Experts have said the documented information points to the Labour leader being cultivated as a possible source rather than serving as an active informant.

The pair are said to have first met after Mr Sarkocy received a tip-off from a 'very important Labour MP' who worked within the trade union movement at the time. On Thursday night, a spokesman for Mr Corbyn said: 'Jeremy was neither an agent, asset, informer nor collaborator with Czechoslovak intelligence. These claims are a ridiculous smear and entirely false.

'The former Czechoslovak agent Jan Sarkocy's account of his meeting with Jeremy was false 30 years ago, is false now and has no credibility whatsoever. His story has more plot holes in it than a bad James Bond movie.'

Labour officials pointed out that Svetlana Ptacnikova, director of the Czech Security Forces Archive that keeps documents of the StB, said Mr Corbyn was 'neither registered [by the StB] as a collaborator, nor does this [his alleged collaboration] stem from archive documents'.

A Labour spokesman said: 'The former Cold War Czechoslovak agent Jan Sarkocy is a fantasist, whose claims are entirely false and becoming more absurd by the day.

'These ridiculous smears should be given no credence whatsoever.'

A spokesman for John McDonnell added: 'These are ridiculous and false allegations.

'John never met any Czechoslovak or Soviet agent, nor visited the Soviet or Russian embassy and has only visited Guildford once in his life, which was last year for a Labour Party public meeting.'