Brown job dit from the hard of hearing:
Mrs Thatcher on victory tour of the Falklands after the war. Someone thinks it would be a good career move to let her fire an artillery piece.
This particular gun has a small metal seat for the firer. Thatch balances her generously proportioned iron posterior on the tiny seat and reaching for the firing cord asks:
"Will this thing jerk me off?"
Collapse of stout party! Apparently she was quite prone to unintended double entendres.