The signals that the ban is coming have been there for decades. Professor David King, former chief scientific advisor to the UK government, suggested a ban on petrol cars in 2002 (http://www.evuk.co.uk/hotwires/rawstuff/art33.html). That would have been a bit early for a ban in my opinion, but had the government heeded his advice and put in a legally binding ban to come in from, say, 2015, then the UK would be well ahead of the curve and would have created tens of thousands of jobs in the electric vehicle industry.

It's also worth pointing out that the 'ban' doesn't ban the sale of all ICE cars - hybrids are still going to be available for sale until at least 2035.