And, fashionably, it involves a bus. Although it’s not so much campaigning for the Liberal Democrats as for sanity in general and the right of the taxpayer to not have their money used as kindling.

Here’s what gives:

Every Tuesday, at 9.45am precisely, a 50-seat executive coach draws up at a bus stop outside Ealing Broadway station in West London. No one ever gets on and, a moment later, it departs – empty – on a 70-minute trip to Wandsworth Road in South London.

Once there, it waits for two hours and 15 minutes before returning, again carrying no passengers. Welcome to Britain’s most luxurious bus service, paid for by the taxpayer, immaculately clean, punctual to the second and which the Government is trying desperately to keep secret.

This service, funded by the Department for Transport, is not advertised on any timetables or departures screens, and staff at the stations it serves are not even aware it exists.

And for why?

By running a weekly bus, ministers can claim that a service still operates and avoid the legal requirement to hold a public consultation…

The Department for Transport is using a loophole in the law governing rail closures that allows ministers “to secure the provision of substitute bus services if a passenger rail service is temporarily interrupted or has been discontinued”.

The article does not explain fully why the service goes unadvertised, but I imagine the reasoning is that it would quickly become overcrowded and be instantly exposed as an inadequate substitute for the rail service (I can’t imagine it’s quicker, either). In which case, surely, part of the solution is just to run more buses. Or would that be too expensive? But then one bus isn’t expensive?

I am confused. Your mission, London Lib Dems, should you choose to accept it, is to find this bus and ride it, then report back to your handlers at Lib Dem Voice.