Your industry chooses not to train people properly so your inflow of new staff is lower than the replacement levels needed. Importing immigrants after they have been trained by somewhere else is a cost-effective way for your industry to cut costs but it means that the people in this country that could be doing the job if the training opportunities existed and the wages weren't kept at rock bottom are choosing to do something else/easier for the same money.
Far too much immigration is because businesses/industries don't contribute to training the staff they need.
*Edit - I include the NHS in that. The government scrapping bursaries and whacking up student debt makes a lot of healthcare roles unattractive and the BMA restricts Dr training roles so we don't have anywhere near enough "homegrown" Drs. There is no shortage of people that want to be doctors and have the educational achievements to do it but we restrict the numbers.
Largely incorrect about construction.
So, lets assume the training is the responsibility of the employer:
You can't train people who don't apply and don't stick around, but also construction and utilities generally doesn't need training for the start, for basic labour roles (which is where 99% of site staff start). It's like an extremely basic H&S test and a CSCS card (£50 total) and you're good to go, that's kind of the point. Then once people stick around for more than 5 minutes that's when they start to get trained on the thousands of various construction courses. This happens as main contractors and clients want (insist) your lads have them (for the best sites), and it makes sense for the lads to have them, plus they're heavily subsidised. Our lads have about 10-20 courses they cycle through which need renewing every few years, but we work on rail, national highways, national grid etc.
But, training doesn't need to be the responsibility of the employer:
Anyone can do 10 courses(for about £1,000 total), and then be immediately a lot further up the chain than most of the other people with <3 years experience. Next to no young lad (or lass) does this of their own accord, but it's a massive time saver and effective proof of dedication/ willingness to work. Doing this alone could get you a 30k job extremely easily, which then only goes up, as you wouldn't be a labourer for long (even if they were extremely average).
There are even loads of free courses and grants, plus the CITB takes money from every construction company to put into a big pot which then gets dished out to anyone who wants it, so basically anyone who wants to do courses can either get them free or extremely cheap. The training is readily available, it's easy, it's quick, and it's cheap.
The wages in construction aren't rock bottom, a labourer with a £50 CSCS card can get a job in the North East on ~£15-17 an hour, and do as much overtime as they want, easy to get an "average" wage just doing that, if willing to work. If they stick it out and get other tickets then 30k+ is simple with no responsibility for others/ no supervision etc.
Even a small digger driver can easily get ~35k minimum, and you can get the ticket to do that for <£1,000, and you can basically sit in the digger all day.
None of the above even need any education really, so there's no barrier to entry for anyone from the UK, and with English as a first language they naturally end up higher up the pecking order.
If they're willing to travel and stay out overnight etc then pay is even higher and obv get meals and hotels paid for etc.
The main problem with construction is apprentices, too many companies are allowed to use this as basically slave labour, but this is more electricians, joiners, plasterers, brickies etc. The young lads don't learn much just carrying tools and tidying up etc, it's not what the scheme was designed for. This is what maybe puts a lot of lads of, but those are more jobs related to house bashing.
Students who do courses in needed degrees are paying too much and none of them should be paying interest on student loans, that's a **** take, especially when those before them got the courses for nowt and obv paid no interest. But, I can see the argument for paying something or a mechanism where people have to pay if they drop out or don't end up using their degree, as it's unfair for the taxpayer to foot that bill. To me footing the bill/ risk of that is worth it to the taxpayer.
Far too many drop out of degrees though or don't end up in a role related to their degree, or at least that's how it was when all my mates were going through uni. Maybe it's better now since the fees set in. In my day half dropped out, and seemingly the only ones who stayed in their degree industry were largely the computer science lot who are all now web/ app devs or database guys. I suppose the latter could be self taught with more relevance to specific roles, and for cheaper these days mind.
Restricting Dr training roles seems nuts, what are their reasons for that? They must give some reasons?
Do people drop out, or are the courses funded by BNA or something?
Do people get trained and then go abroad for better pay?
A doctor is what, a 7 year medical degree? Probably a £200k cost to doing that for 7 years for course fees and expenses? Or can a nurse do a top up degree to become a doctor, or something like that?