I cant see any evidence that he commented on it. However, its likely he did approve, to an extent. Cabinet notes from 24th Feb 1954.

Winston Churchill. Tory Party won´t want to accept responsibility for makg. law on homosexuality more lenient – or for maisons tolerées. But, w´out enquiry - i) could we not limit publicity for homosexuality, as was done for divorce? ii) persons convicted shd. have opportunity to apply for medical treatment. .Otherwise, I wdn´t touch the subject. Let it get worse – in hope of a more united public pressure for some amendment.

http://www.pinknews.co.uk/2007/08/06/archives-reveal-churchills-cabinet-discussed-gays/

Note: This is a transcription from a website. I havent seen the source, but it looks credible.

So not only may he have approved, but even suggested the punishment was relevant.

Note2: This was in 24Feb 54, 6 months or less before Turings death, Turing had already undergone this punishment and had already ceased it at the time of the memo.

You should be aware Churchill was born in the 1800s and was thus limited in his viewpoint. Furthermore current opinion at the time by many was that Homosexuality was a sexual deviancy, like Paedophilia or Necrophilia is today, and thus subject to valid legal repression.

Edited, thanks to Ezterhazy Primary Source for his quotes. http://www.nationalarchives.gov.uk/releases/2007/august/sexualoffences.htm

I've a book on Churchill in which there is the following attributed quote: "Homosexuals might indeed be a security risk, not so much because they might be subject to blackmail, but because they often feel themselves alien and apart from mainstream of the country, like a black in a white country or white in a black one. "

This is the only reference that I've ever heard about what his general feelings may have been on the subject. Based on this, one gets the impression that he probably didn't approve. But he was too shroud of a politician to say much on the subject.

I don't have the original source, but this is quoted in: "Churchill in his own words", with reference to Montague Brown 219-220.

Follow-up question: Did Churchill comment on the Nazi extermination of homosexuals?