The saying attributed to Winston Churchill rejecting the rule against ending a sentence with a preposition must be among the most frequently mutated witticisms ever. I have received many notes from correspondents claiming to know what the “original saying” was, but none of them cites an authoritative source.
The alt.english.usage FAQ states that the story originated with an anecdote in Sir Ernest Gowers’ Plain Words (1948). Supposedly an editor had clumsily rearranged one of Churchill’s sentences to avoid ending it in a preposition, and the Prime Minister, very proud of his style, scribbled this note in reply: “This is the sort of English up with which I will not put.” The American Heritage Book of English Usage agrees.
The FAQ goes on to say that the Oxford Companion to the English Language (no edition cited) states that the original was “This is the sort of bloody nonsense up with which I will not put.” To me this sounds more likely, and eagerness to avoid the offensive word “bloody” would help to explain the proliferation of variations. A quick search of the Internet turned up an astonishing number. In this era of copy-and-paste it’s truly unusual to find such rich variety. The narrative context varies too: sometimes the person rebuked by Churchill is a correspondent, a speech editor, a bureaucrat, or an audience member at a speech and sometimes it is a man, sometimes a woman, and sometimes even a young student. Sometimes Churchill writes a note, sometimes he scribbles the note on the corrected manuscript, and often he is said to have spoken the rebuke aloud. The text concerned was variously a book manuscript, a speech, an article, or a government document.

Here is just a sample of the variations circulating on the Net: