What are you on about?
Studies have repeatedly shown that immigrants to the UK contribute positively to GDP. That distribution is of course uneven and there are those who receive more than they can pay in, but the net contribution of migrants to GDP is positive and has been for decades.
Further, the population is growing by about half a million a year. Significant, of course, but absolutely not the cause of recession.
No prizes for guessing who takes the largest proportion of their money out of the economy during recessions.
Edited to give the benefit of the doubt that I might have misunderstood your post.