There has always been immigration to the UK, and there has always been race/religion/cultural opposition to it. There was fear mongering about the Jews, The Irish, West Indians and so on.
Immigration has increased in the last 10 years, of that there is no doubt. This was done to fuel the economic boom that the country enjoyed until about late 2007. Since then, immigration laws have tightened and with the economic downturn, we have seen over a 40% drop in the number of immigrants coming into the country in the last year. The new 'points system' that has been brought in should see that further reduced.
In general, I do not think it has been bad. It seems worse now, because we are in a recession and a dark skinned person on the street is a far easier scapegoat than a faceless banker or property tycoon.