I don't know whether you would class this as "evidence", but all I can do is cite acouple of cases from my locality.
You misrepresented me by saying.."Your point of view is that the government uses immigration as a tool to bring wage ratesdown"..when what I actually said was "the govt encourages immigration to control wage rates"....as you may know it is illegal to force workers to except less than the minimum wage.

I mentioned earlier about the many fish farms round here who pay the minimum wage, they used to employ local workers on the minimum wage...which is basically starvation wages.
The fish farm company decided to keep the minimum wage rate yet increase the number of hours worked for some and bring in short term contract work for others....this being advantageous to the farm company financial terms, but means that the workers were left with less money at the end of the week.

A dispute started which ended with some of the workers leaving and the rest returning to work on the new terms.
The shortfall in staff is made up by bussing in 25 Eastern European workers daily from the nearest town....by public transport of course subsidised by the taxpayer.

The most common other cases are in the building trade.
A local developer had run short of cash and applied to an agency which suppies Polish building workers at £10 per hr, far below the daywork rate for a local tradesman.....the job took months to complete....in fact it was never properly finished as the Polish gang disappeared before completion.
I was asked by the developer to finish the job and on inspection I found it to be a real "botch up" the workers involved were obviously not tradesmen. I finished the job to the best of my ability but much of the work will need to be undone.
The deveoper is very angry, but as I said to him,"did you really expect to get a decent tradesman for £10 per hour?

This scenario is occuring on quite a large scale in Scotland.

I also know quite a lot about the Asian community especially in Glasgow, who are indeed very hardworking, but the problem my Goan friend tells me is a social one.....the Asians have no intention of integrating with the indigenous Glasgow people whom they see as people of low morallity, given to drunkeness, violence and godlessness, in fact, as you "liberals" would say they are bigotted against the Scots.

I expect you to start a new thread complaining about this forthwith!