Ok, so you think there is a skills shortage in the building trade, and you believe that it is because British people are going to university rather than into trades. The industry on the other hand, think it will be because tradesman will quite probably not qualify for any kind of post-Brexit visa, and that the existing government support isn't working.
I'm sure you're aware of the apprenticeship levy, which was designed to incentivise apprenticeships of the kind you appear to love. It's widely regarded in the industry to need tweaking as it isn't working as well as it might at the moment, but of course we don't need to leave the EU to do that. You've also got the Construction Industry Training Board levy, which is taken from any employer with a wage bill of over £80k to be invested in training for the industry.