More tea vicar

Google throws up www.sillyjokes.co.uk/ fart_machine/fart_slang.html
is response to "more tea vicar" suggesting that the phrase did originate a faux polite response to a public fart. (though I can't find the phrase on the page).

If I had to choose, "let Polly out of jail" would be my favorite.

Oliver Cromwell might have said "Who farted".

Hmmm. I don't think that has the same je ne sais quoi as "let Polly out of jail."