Ah, yes, it was actually known in much of the world what the Germans were doing, or at least rumored/suspected. Still, Churchill said and did a lot of questionable things during his tenure as PM.A lot if it is in record too, like his comments on Gandhi*:
Statements about Gandhi

Churchill had strong views on the man now widely respected for his work in advocating self-determination for India.

"It is alarming and nauseating to see Mr Gandhi, a seditious Middle Temple lawyer, now posing as a fakir… striding half-naked up the steps of the Vice-regal Palace," Churchill said of his anti-colonialist adversary in 1931.

"Gandhi should not be released on the account of a mere threat of fasting," Churchill told the cabinet on another occasion. "We should be rid of a bad man and an enemy of the Empire if he died."

It's unfashionable today to question Gandhi's non-violent political tactics. He is venerated in much the same way as Churchill is in the UK. But for years he was a threat to Churchill's vision for the British Empire.

"He put himself at the head of a movement of irreconcilable imperialist romantics," wrote Boris Johnson in his recent biography of Churchill. "Die-hard defenders of the Raj and of the God-given right of every pink-jowled Englishman to sit on his veranda and… glory in the possession of India."

"Churchill was very much on the far right of British politics over India," says Charmley. "Even to most Conservatives, let alone Liberals and Labour, Churchill's views on India between 1929 and 1939 were quite abhorrent."

He was vociferous in his opposition to Gandhi, says Toye, and didn't want India to make any moves towards self-government to the extent of opposing his own party's leaders and being generally quite hostile to Hinduism.

Churchill's stance was very much that of a late Victorian imperialist, Charmley adds. "[Churchill] was terribly alarmed that giving the Indians home rule was going to lead to the downfall of the British Empire and the end of civilisation."

Younger Tories like Anthony Eden regarded Churchill with great mistrust during the 1930s because of his association with hard-line right-wingers in the party, he says.

"People sometimes question why on Earth did people not listen to Churchill's warnings about Hitler in the late 1930s," says Charmley, "to which the short answer is that he'd used exactly the same language about Gandhi in the early 1930s."

*Yes I know Gandhi was by no means perfect either, but I feel like there are blinders on when it comes to Winston Churchill because of his leadership of the UK during WW2.