Michael Foot flirted secretly with Russia. Jeremy Corbyn is blatant per The Sunday Times

In summary - Comrade Corbyn was the USSR's useful idiot. 

At more length:

'There is no evidence that Corbyn was paid by the Czechs or knew that his convivial Iron Curtain contact was a spy. What is indisputable is that the left of the Labour Party has retained a fatal attraction to authoritarian, anti-western regimes decades after Stalin's crimes were exposed. It is the yin to the far left's yang, the enduring proof that its brand of socialism cannot exist without attaching itself to the tainted and unacceptable "actually existing" models that render it unelectable to saner eyes.

... Long before the wall came down — and the Soviet Union with it — I stopped making even the slightest excuse for a hideous regime. Corbyn has remained a "useful idiot" to this day.

Whether touring East Germany by motorbike with Diane Abbott in the 1970s or lauding the old tyrant Fidel Castro on his death, the Labour leader has fallen for one autocratic regime after another. To be anti-western, especially anti-American, is enough to win his hero-worship.

One of his chief advisers, Andrew Murray, is an apologist for Stalin who left the Communist Party for Labour only when Corbyn was elected. Is this why the House of Commons authorities have yet to issue Murray with security clearance? Corbyn's private secretary, Iram Awan, a pro-Palestinian activist, is in similar limbo. It emerged last week that they are being escorted to their jobs in the leader's office on a visitor's pass.

Corbyn's genuflections to IRA and Palestinian terrorists, his comradely greetings to Hamas and Hezbollah "brothers" and his appearances on Iran's Press TV and RT (Russia Today) suggest that the Kremlin has no need to stuff his pockets with cash: he is a willing accomplice.

We saw this clearly when Corbyn demanded "incontrovertible" proof that the Skripals were poisoned by Russian agents in the spring, even suggesting that samples of the nerve agent novichok be sent to Moscow for testing. His chief strategist, Seumas Milne, another Soviet sympathiser, threw up some chaff about the would-be killers belonging to a McMafia hit squad.

Now that the poisoners have gone on television at Vladimir Putin's invitation and peddled a slew of falsehoods, the Labour leader has gone quiet, as well he might. But the ghost of Agent Boot has been exhumed. While Foot kept his flirtation with Moscow secret, with Corbyn it's in plain sight. More fools us, if we choose to ignore it.'

You can read more here in The Sunday Times 

https://www.thetimes.co.uk/article/Michael-Foot-flirted-secretly-with-Russia-Jeremy-Corbyn-is-blatant but don't expect on the Labour Party's propaganda arm, the BBC.