As a reminder, Vinty said [paraphrased] why are so many people coming here by boat? You said, they aren't. The UK has a problem with illegal immigrants, not the relatively few genuine refugees claiming asylum, or the genuine visa applicants coming here for a better life, bringing skills and qualifications.
Looking at per capita is as relevant as per SqM of land. The UK is a small Island for its population size. Only Belgium and the Netherlands having significant populations trump the UK in terms of population density.
Why would you want to deny the fact that the UK has an illegal immigrant problem? Roughly 1/2 to 3/4 of a million people living here.
Are you not concerned by this for example?
Why are Albanian migrants coming to the UK and how many have arrived?
www.bbc.co.uk