My personal objection is that my ancestors have worked hard for centuries to build Britain up to what it is now and it's complete BS that any unskilled person from Poland can get a £30 flight over, sign up with an agency and get the benefits of that hard work while we still have 5% unemployment who are all capable of doing these unskilled jobs.
What you're saying here is your ancestors worked hard for centuries to give us the opportunity to clean toilets and you're outraged because many Britons are not interested in doing that. Why don't you try taking a part time job cleaning toilets and thus make your ancestors proud, eh?

Immigration happens because it is needed. All developed countries use it (with the notable exception of the aging, stagnating Japan) and quite a few have higher levels.
Being against immigration, particularly EU immigration, which provides skilled workers that are closer culturally, makes no sense. Unless of course you are among those who have problems with people who are a bit different than you and your tribe.