There are things the Mayor of London can stop and things he can't or won't.
Last October I wrote to him the following letter:
"Dear Mr Johnson
Over the past couple of decades, the view from Waterloo Bridge - looking east or west - has become one of London's most spectacular, especially at night. I am sure you know this .... Recent roadworks on the bridge have been accompanied by the erection of lots of large posts on the west side in readiness ... for the erection of even larger road signs which will obstruct and spoil the current openness of the bridge and the view. You should stop this from happening ...."
Not my responsibility, came the reply: the bridge is the responsibility of the City of Westminster (north side) and the London Borough of Lambeth (south side). Write to them. So I did, but they didn't answer.
The signs have now gone up including three enormous ones on the central span, all saying the same thing. It's the end of the finanacial year, you see, so you have to find something on which to spend the money.
It's a pity. It was a lovely view. Mr Johnson could still step in and knock some wooden heads together. After all, he doesn't want the view spoiled in Parliament Square.