Immigration is a tool
At times we needed a large influx, and the work was there to make use of them, but the post war period is far different to now when we have very little industry and many area's which were labor intensive also do not exist
Also apart from having a need for migrants there is the assimilation problem IE the more there are the more work and money has to go into that procedure and our Government is lacking in this regard, also lacking is the extra services needed for the large influx of migrants from different cultures and way of life
So there are two problems
There is limited work for them
The numbers have been far too high to comfortably fit them into our society and way of life
So the people do not get a benefit as I expect it is the multi nationals, who pay little or no tax and take their profits out of the country