My English in-laws told me that many of the immigrants, illegal and legal, do the hard manual labor that homegrown Brits don't want to do. For instance on a road trip to Scotland to visit some of my other in-laws, we passed an agricultural field where a group of people were pulling veggies out of the ground. One of my in-laws opined that probably everyone of the pickers was a non-Brit. Gee, where else is there a similar situation concerning people doing work the locals don't want to do?
Additionally we witnessed many foreign trucks on Britains main dual carriageways...four lane highways to us Yanks. The Chunnel has made that much easier.
The local people won't do the work...... for the pay being offered!!!
All the immigrants do is undercut the locals. Many would offer to empty bed pans for a million $$ per year. It's not the work that's the problem, it's the price being offered to do it.