There is a very simple reason that there is a shortage of engineers in th UK. The pay is 5hite and sadly they command little respect from management types who believe that all they need to do to solve all their problems is to shout louder and louder at the people at the sharp end until something happens.
Many young people with the apptitude to become an engineer realise early on that there are many easier and more lucrative ways of earning a crust.