Conservative MP Ben Bradley has been forced to apologise to Labour leader Jeremy Corbyn after a tweet linking him to Communist spying.
Ben Bradley said his comment was "wholly untrue" and promised to make donations to two charities, the Independent reported.
Both Corbyn and Labour's popularity have remained largely steady despite two weeks of headlines alleging he was on the payroll of Czechoslovakia's secret service during the Cold War.
According to a YouGov poll for the Times released on Saturday (24 February), support for the Labour party has grown by one point to 42% since the claims were first published, while the Conservatives have remained stable at 40%.
Meanwhile, just 8% of respondents said their opinion of the Labour leader had worsened after the allegations first saw the light of day, while 6% said it had improved.
For 64% of those surveyed, the story had not altered their perception of Corbyn at all.
Earlier this month, The Sun published a story alleging the Labour leader met a top intelligence operative from Czechoslovakia during the 1980s. The story, which is based on what the newspaper described as "secret files", also claimed Czechoslovakian state security files listed Corbyn among their agents and sources.
The Labour leader, who was reportedly identified as "COB" within the network of Soviet spies, was "very well informed" of people in contact with "anti-communist agencies".
However, a spokesman for the Labour Party leader swiftly dismissed the claims, insisting that while Corbyn had met a Czechoslovak diplomat in London, he did not provide any information.
"Like other MPs, Jeremy has met diplomats from many countries. In the 1980s he met a Czech diplomat, who did not go by the name of Jan Dymic [the name quoted by the Sun], for a cup of tea in the House of Commons," he explained.
"Jeremy neither had nor offered any privileged information to this or any other diplomat. During the Cold War, intelligence officers notoriously claimed to superiors to have recruited people they had merely met. The existence of these bogus claims does not make them in any way true."
The claims have also been dismissed by Czech authorities, who say there is no evidence Corbyn was ever a paid informant.
"When you compare the documents which [Sarkocy] had written and signed himself with what he is saying today, based on that he is a liar,"Radek Schovánek, Czech Republic defence ministry analyst told the Guardian.