On Monday a report called Putin Sees and Hears It All: How Russia's Intelligence Agencies Menace The UK revealed the industrial scale of his espionage operation in Britain.

The report cites the case of Vladimir Ashurkov, who came to Britain in 2014 after he requested asylum 'due to political persecution' by authorities, according to the Daily Mail.

He fled to London after being intimidated by the Kremlin for supporting the opposition but quickly realized he was being followed everywhere he went.

On one occasion he met a fellow businessman for coffee in a cafe popular with Russians but afterwards became sure that one or more people there were listening in.

His friend "traveled to Moscow the following week and he met with some people from the security services. They knew about our meeting, where we met and what we discussed," according to today's report.

Mr Ashurkov has said he has "learnt to be vigilant at émigré gatherings listening out for who was talking about politics, security and other sensitive topics, aware that they might be informants collecting information and sending it to Moscow."

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"Interviewees ... suggested that anywhere between a quarter and a half of Russian expats were, or have been, informants," the report said.

Some of the spying is flagrant with agents openly gathering outside Russians schools and businesses to intimidate. The men are loudly speaking Russian and eating sunflower seeds, one of the most popular snacks in the country.

Author of the report Andrew Foxall said that the capital is "ill-equipped" to deal with the worrying rise in Russian espionage.

He claims that the country's embassy in London holds a great deal of power and its officials are relied upon to make contacts and find business opportunities in Britain.

Describing the current atmosphere in the UK he said: "There is this increasing paranoia or belief that they [Russians] are being watched, that they need to be careful what they say and to whom they say it and where they speak."

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Last month it was estimated that there are 200 Russian spies in the UK and at least 500 agents providing information.

But if today's estimates are correct then thousands will be passing back information.

The figures come amid an increasing fear of Russian infiltration and espionage in the country following the attempted murders of Sergei and Yulia Skripal in March this year.

Former MI6 chief Sir Richard Dearlove said today's report "forcefully reminds us that Russian intelligence activity in the West is still large-scale and intrusive."

He told The Times: "We need to devote significant resources and expertise ourselves to monitoring and blunting this threat to our national security.

"As during the Cold War an effective counterintelligence capability remains an essential part of our own intelligence and security community."