Liam Fox claims Jeremy Corbyn was 'very useful to the Soviet Union', despite Tory MP's apology over spy claims

Tory MP Ben Bradley was forced to issue a grovelling apology over false spy claims about the Labour leader

Liam Fox has waded into the row over Jeremy Corbyn’s Cold War links by claiming the Labour leader was “very useful” to the Soviet Union and “undermined” national security.

Just a day after his Tory colleague Ben Bradley issued a grovelling apology for making false claims about Mr Corbyn’s meetings with a communist spy, the International Trade Secretary said the Labour left had been “useful idiots” and acted in a way that “damaged” the country.

Critics of Mr Corbyn have seized on allegations that he met with a Czech agent, who was posing as a diplomat, on several occasions in the 1980s, but the polls suggest that the attacks have had almost no effect on the Labour leader’s popularity ratings.

Mr Corbyn has dismissed the claims as “ridiculous smears” and demanded an apology and a “substantial” donation to charity from Conservative MP Ben Bradley, who tweeted false claims about his links to Cold War agents.

Mr Bradley’s Twitter apology has received more than 32,500 retweets so far.

Mr Fox said it was right for Mr Bradley to apologise, telling the BBC’s Andrew Marr Show: “If you say something that is untrue you have to say so.”

However he distanced himself from Defence Secretary Gavin Williamson’s claim that Mr Corbyn had “betrayed” Britain by meeting Jan Sarkocy, a former agent with the Czechoslovakian security service.

Mr Fox said: “I certainly think that the Labour left were the Soviet Union’s useful idiots during that period.

“I certainly believe and I think it is true that Jeremy Corbyn and others were very useful to the Soviet Union during the Cold War because they undermined the arguments of the West.

“I think in the broadest sense he was undermining the security of our country by siding with the Soviet Union in that argument and I think that was very damaging to the country.”

He said it was “very clear that Jeremy Corbyn and his fellow left wingers were undermining the case for our security”.

Commons Leader Andrea Leadsom also weighed in, saying Mr Bradley was a “very good man” and he was right to raise concerns about some of Mr Corbyn’s friends and allies.

She told Sky News: “He has apologised for a tweet which accused Jeremy Corbyn of some things which Jeremy Corbyn was not shown to have done to have been guilty of and he has done the right thing in apologising profusely for that.

“I think he was right in his concerns about some of Jeremy Corbyn’s friends, I think he is right to have raised that point.

“I think it should be of concern to all of us that Jeremy Corbyn does seem to have friends amongst people who are not acting in the UK’s interest.”

The Labour leader accepts he met a Czech diplomat once in 1986, as one of many meetings with ambassadors, politicians and activists, but insists he had no idea the man was a spy.

Mr Sarkocy – who claims the Czech government was responsible for organising Live Aid – has been branded a fantasist by Mr Corbyn’s allies.

The Labour leader’s spokesman also challenged records of supposed meetings, as Czech secret service files recorded one as taking place in the House of Commons on a Saturday when the Labour MP’s own diaries record he was attending a conference in Derbyshire.

A Labour Party spokesman said: “Liam Fox should focus on his job and not give credence to claims that everyone knows are entirely false and ridiculous.”