The shortage of skilled trades people is mainly due to so many school leavers entering university on useless courses, under the illusion of immediately getting a high paid job when they leave. The reality seems quite different, with courses like gender studies, it's hardly surprising. If learning a trade as an apprentice was not looked down on so much you would have a plentiful skilled British workforce and so many ex students wouldn't be on the internet, claiming cerebral superiority over their elders, but without work, too precious to get their hands dirty.
A good friend of mine retrained as a plumber and electrician having graduated in Economics & French a few years earlier. He jacked it in after a couple of years because in his area he just couldn't make a living off it, either getting paid below minimum wage (and having to supplement with 'cash for petrol' / benefits) or signed up allegedly full time on a salary but then getting laid off as soon as a the job was done. His vision had been to get experience and then go solo but he said there just wasn't the money in it at the time in that area, e.g. changing a tap would be a 15 quid job, you couldn't get away with charging a ton for that.
In essence was more than happy to get his hands dirty, he'd do all sorts on site carrying the hod etc, also done jobs as a plasterers mate. He didn't look down on the trade at all, he is much happier doing practical stuff than being stuck in an office, he just couldn't afford to eat working in trades during the recession.