The UK has never experienced such immigration in such a short period of time before.
This is not correct. Perhaps you could say in recent times...
"From 1670 to 1710, between 40,000 and 50,000 (French) Huguenots moved to England." At the time the population of England was 5,240,000. See this site for more information.
At this time it is thought that 400,000 Polish people have moved to the UK where the current population is about 60,587,000. See this site for confirmation:
It is also thought that one in every four English people have French Huguenot ancestry.
These sites have more information on this: