Shadow Chancellor John McDonnell has made Winston Churchill a "bad guy."
The Laboratory Heavyweight commented on Mr. Churchill's dealings with striking Welsh miners during the House Secretary's 1910s.
Mr. Churchill's decision to send troops to support the Tonypandy police riots has long been the subject of a historical debate.
In a question and answer session with the Politico website, Mr. McDonnell was asked, "Winston Churchill, hero or villain?"
The Shadow Chancellor said, "Tonypandie – Badwicht".
Mr. Churchill ordered 200 police from the Metropolitan Police in Tonypandy, with a number of Lancashire Fusiliers in Cardiff in reserve.
The soldiers were finally called to the village of Rhondda Valley to deal with the situation.
The warlord, who was later knighted, was voted the largest Briton in a BBC poll in 2002.
Tory's deputy Sir Nicholas Soames, grandson of the former conservative prime minister, told the Daily Telegraph: "Frankly, it's a very silly and stupid thing that's said to advertise confidently.
"I think my grandfather's reputation can withstand a public relations attack emanating from a third-rate, Poundland Lenin. I do not think it will shake the world. "
Member of Parliament Ian Austin made it clear that he did not agree with Mr McDonnell's comments by posting a picture of a figure of the warlord he holds at home in the social media.
Mr. Austin Tweeted: "See who takes pride of place on my mantelpiece in Dudley: a true British hero, the greatest Briton, the man who has motivated Britain to defeat the Nazis and not just fight for our freedom, but also for the freedom of the world. "