Immigrants aren't the problem, the system is.
I don't think the problems that the UK has can be blamed simply on immigrants. Many immigrants (the majority? I don't know.) just want to make a better life for themselves and their families and are prepared to work (often much harder than UK citizens) to do it and, by so doing, make a positive contribution to British society. Of course there are many who just want to take advantage of 'the sytem' of benefits that the UK has. But then there is also a significant number of 'native' British citizens who want to do the same - sponge off the system. I'd be interested to know, if it is possible to find out, what proportion of benefit claimants are 'immmigrants' and what proportion are 'native' British.
I have as much interest in apportioning blame as anyone. I am retired and live in Thailand principally because I can't afford to live in the UK. I still pay tax, as I did throughout my pretty full working life, on my pension and on the (very) modest rental income from the flat I still have in the UK. Yet I receive none of the benefits (I have never claimed benefits in the past) that resident UK citizens take for granted. I get no free healthcare, even when I return to the UK on 'holiday', and my state pension will not be indexed when I get it (too soon, unfortunately!) - to name but two.
It's a natural gut reaction to target immigrants in receipt of benefits but, if the UK didn't have the comparatively generous benefit system it has, then perhaps at least, the immigrants and the UK natives who just sponge off the system and DON'T make any contribution would be discouraged and people like me can then only lay the blame for Britain's economic and social woes on successive British governments where it really belongs.
The question of integration of immigrants into the British 'way of life' is wholly another question raising similarly negative gut reactions and is, perhaps, even more insoluble a problem. I'm as guilty as many others of fearing and resenting many immigrants 'ghetto' mentality and refusal to become 'British' (whatever that is). But that's another story and I've prattled on long enough!