Firstly, I would imagine the London mayor would want the ULEZ to kick in well before 2020, as he will be fighting an election campaign by then and any potential successor could vow to scrap it before it gets off the ground.
Secondly, this could have unforeseen consequences as, possibly, lots of banking jobs could have already left London by then and this could drive some small businesses to relocate outside the zone.
I wouldn’t try to predict the outcome of all of this, but it may rebalance the economy away from the capital.....a bit.....and that might just be one of the intentions. There are a lot of ifs, ands and buts at this stage and, no doubt, many affected groups will be making their views clear in time.
Let’s face it, we have to do something about the amount of pollution in our big cities, people’s health is being severely affected. So, if the powers that be can reduce the smog and coin it in at the same time, well...win win...for them.