Transport secretary Douglas Alexander - and, presumably, Gordon Brown - wants to have a debate about using road charging to reduce congestion by 25pc despite a 1m-signature petition against the idea.
Well, it may or may not surprise Mr Alexander to learn that someone has already thought of a Big Idea for reducing the number of motorists off the road. It's called public transport.
It strikes me that there is potential for some very interesting political cross-dressing on this one if David Cameron wants to defend the cost of motoring as free at the point of delivery while at the same time underlining his environmental credentials by ploughing the proceeds of green taxes into trains and buses.
Could the Tories, the party of Dr Beeching and rail privatisation, really become the party of public transport? Stranger things have happened.