Then why not help wages go up, or tax them less? The unions here have been very destructive in that they only take care of their older cadres and stiffing the younger ones, and at the same time only targeting industries where they already had it good.. Migration has indeed put downward pressure on them, but thus far our respective governments have done very little to counteract this or even helped driving them down. Our welfare states are a different problem, where the problem actually lies quite close to part of the brexit problem as well. Most of the welfare has been build up when all of Western Europe had a population dividend from the boomer generation. It was easy to pay for very generous welfare when an outsized part of the population was working and paying into it. Now that that generation has largely retired we are suddenly facing an increase in payouts and decrease in taxes. Part of the influx of Eastern European workers actually helps with this problem, as indicated by the net contribution number the UK has from European workers. The boomer gen is also one of the most political active ones, so it's very hard to tell them that what they paid for for others isn't fair to ask from the current working generations. So, welfare might need to come down a tad and wages need to come up, seems like something a national government could create policy for.
Fwiw, there is only cooperation on military matters and that's also what Interpol is. Not really dictated by the EC but agreed upon by the states. Migration is part of the common market, unless you are talking about migration from outside of the EU. And btw, a lot of those poles are going back because wages back home are going up quickly due to a shortage in workers there..
Scandinavia and the U.K. Both created a welfare state aimed at keeping the population growth above that 2.1 number back in the day, whilst keeping the poors happy with a handout while they focused on the mid incomes. If you make it possible to live better of three child welfare payouts then of a low income job (uk) then you can expect them to breed and make use of that system. Again, this is a problem not of migrants, although it's infinitely easier to blame them, but a problem of policy. One of the national governments I might add, not the EU.
And lastly, the EC has put forth a proposal re migrants Eastern Europe. See solidarity fine
That is not as easy as you make it sound. On large construction projects the trade unions fight a loosing fight, as the workers know, if they sign up and start demanding the correct wages. They will be kicked to the curb and someone else is standing in line to take over. The contracts for the work also go through 3-4 companies, so even writing it in to the contracts doesn't work, as they are essentially self-employed subcontractors.
Another issues that they are happy with €5 an hour over €30 an hour a dane should have, as it's more than they would make in Poland etc. and it means they can send the money home, while living in some barack town with the rest of the workers. This creates a bunch of issues including increasing unemployment and more pressure on the public sector, to pay welfare, reeducation etc. etc. (I actually know multiple builders who live of fixing EE workers shitty workmanship).
The problem isn't that there are fewer people to carry the load, the issues is that the labor force participation rate is lower than it was then and there are fewer people employed by the private sector vs. public. The last part is especially important, as they are the ones who essentially create the money, that the public sector needs.
People keep saying the influx of EE, ME and african migrants help take someone of the load of the public sector and stop them from going bankrupt. This just isn't true we spend around €26 million a year on unemployment welfare for EE workers and the ME and africans have an unemployment rate of over 50%. They contribute with aprox. €295 million a year (2014), while costing the society €2 billion a years, so that is a deficit of €1.8 billion a year, it has to be a lot higher now. So no they are not an asset as is. The only thing that would solve the giant drainage of the western welfare states, is to either start kicking non EU migrants out ASAP or getting them in employed on the same level as native nationals and before EE workers.
I'm a conservative liberal, so we can very quickly agree a large part of the solution is to lower the taxes and get people spending and getting some of the jobs, that have been exported to Asia etc. back. And more importantly remove the incitament and living standard of people who are able to work welfare payouts.. Sadly the largest parties here are socialists are they don't get that, so they refuse to lower taxes, but they are still talking about increasing our competitiveness. At least they have started to lower the welfare amounts etc.