Unfortunately, in the U.K., there is no law to prevent anyone from calling themselves an engineer - the Jack of all trades problem - whether they fix toilets (sanitation engineer), service cars (auto engineer) or someone worrying a piece of wood with nothing more than a blunt penknife (design engineer).
Which is why many engineers worthy of the title become chartered; to differentiate themselves with a superior level of qualification, evidenced experience in a responsible job role that cannot be performed by a technician, peer reviewed and enrolled into a Royal Institution which sets the standards for their discipline.
There is a very big difference between an engineer responsible for designing a nuclear reactor with the guy who fits exhausts on a car.
The description of 'engineer', in the general publics view, covers everything in between.