UK's left-wing Labor leader Jeremy Corbyn under fire for alleged Soviet collusion

Jeremy Corbyn, the far-left leader of the UK Labor Party, lashed out at the British press Tuesday after allegations surfaced that he, along with other high-profile members of his party, colluded with Soviet spies during the Cold War.

Former Czech spy Jan Sarkocy told The Sun that the Labor Party leader was in collaboration with the Soviet-era Czechoslovakian intelligence agency StB in the late-1980s when Margaret Thatcher was prime minister.

As Labor leader, Corbyn is in line to be prime minister should his party outperform current Prime Minister Theresa May’s Conservative Party in the next election.

But Corbyn's position is now under threat after Sarkocy claimed that Corbyn was a paid collaborator and that he knew that Sarkocy was a spy, not just the diplomat he posed as.

"Corbyn was recruited. He also received money," the spy said, adding that his code name was “COB.” He also claimed that during multiple meetings between 1986 and 1987, Corbyn passed along information about a British crackdown on Communist spies.

The head of the Czech spy archive told the outlet that while they could confirm Corby and Sarkocy met for talks, Corbyn was never registered as a collaborator and would not have known Sarkocy was an agent.

Labor cited that response as proof that the claims were 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,” a statement from the Labor Party said. Corbyn has also described the claims as "increasingly wild and entirely false."

According to the UK Daily Telegraph, Sarkocy said Corbyn was just one of at least 15 senior Labor figures who shared information with Soviet agents. Those named include former London Mayor Ken Livingstone (who was nicknamed “Red Ken” for his hard-left views) and current Shadow Chancellor and close Corbyn ally John McDonnell. Both have denied the claims.

Defense Secretary Gavin Williamson described the revelations about Corbyn as a “betrayal of this country.”

“Time and time again he has sided with those who want to destroy everything that is great about this country, whether it is sympathizing with terrorists, backing rogue regimes, or cozying up to those who want to inflict pain and misery on the British people,” he said.

May increased pressure on Corbyn, backing calls for him to be "open and transparent" about his links. On Wednesday, she went so far as to mock him in Parliament.

"Can I congratulate the Right Honorable Gentleman, because normally he stands up every week and asks me to sign a blank check -- and I know he likes Czechs..." she quipped.

La primera ministra de Gran Bretaña, Theresa May, interviene en una reunión durante una visita oficial a Beijing, el 31 de enero de 2018. (AP Foto/Mark Schiefelbein, Pool)

Prime Minister Theresa May has called for Corbyn to be "open and transparent" about his dealings with a Czech spy.  (AP)

But Corbyn has pushed back with a fiery, conspiracy-laden video statement, in which he accused “media bosses” of publishing smears because they are worried about a possible Labor government.

“They are right to be,” a wide-eyed Corbyn said in the video published Tuesday.

While saying a free press was “essential for democracy,” he then claimed that the press is “controlled by billionaire tax exiles who are determined to dodge paying their fair share for our public services” and who resort to “lies and smears.”

“Well, we’ve got news for them,” he said, brandishing a humorless smile. “Change is coming.”

The claims fit in to a broader narrative pushed by Corbyn opponents that he sides consistently with opponents and enemies of The Telegraph reported last year that Britain’s MI5 opened a file on Corbyn over his links to the IRA in the '80s and '90s, amid fears he was a threat to national security and suspicions as he attended events to honor dead terrorists.

In 2013, he thanked then-Venezuelan President Hugo Chavez for “showing that the poor matter and wealth can be shared.”

In a 2014 interview with Russian television, Corbyn blamed strife in Iraq on “Western meddling” and compared U.S. troops to ISIS.

“Yes, [ISIS troops] are brutal, yes some of what they have done is quite appalling; likewise, what Americans did in Fallujah and other places is appalling,” he said.

Adam Shaw is a Politics Reporter and occasional Opinion writer for FoxNews.com. He can be reached here or on Twitter: @AdamShawNY.