Aerfen - you do realise that most of the English "ancestors" were themselves immigrants to England?
That there are very few of "pure" original inhabitants of "England"?
And even if you're just talking 19th and 20th Century, much of our "infrastructure" was built by Irish "navvies"? Or that a lot of the UK "wealth" was built on the back of colonial riches? Or that out royal family is itself an "immigrant" family? although maybe they fit the definition of scroungers 
But it would appear you would like us to go back to past days, when it was the Irish, Jews or Blacks who were viewed as the "scroungers" or "othered", with signs such as "No Irish or No Jews" (and later, "No Blacks") were acceptable. 
I wasn't born in the UK - but on one side of the family have a lineage supposedly going back to Henry VIII (wrong side of the blanket
) Depending on how far back you go, I have a mix of German, Swedish, Danish, South African, Irish, French Hugeonot, Australian and English. Now whose heritage should I be proud of? As it happens, it's the Scottish heritage - the one country that as far as I am aware, I have no "blood" link to (although I do now via ds
).
I have spent many years "contributing" to Scottish (and English) infrastructure. Does the fact that I wasn't born here make that contribution less valuable or somehow suspect? Or is it ok because I'm naturalised British? (Which my dad did as quickly as possible for both himself and his children - my mum already had a British passport by pure accident of circumstance, born during the war while her dad worked here - as his passport was not one that was good for travel).
What about those EU immigrants who have "worked" on building infrastructure? Will that be the criteria you would suggest using to "allow" people to stay? But that would include some of those Poles that you seem to have a thing against? 
What about doctors, like my dad or many of my friends (South African, Kiwi, Maltese, Australian, Indian)? Or just plain sales people (Icelandic, Polish, French)? 
I find your comments resenting immigrants "utilising infrastructure built up by ancestors over decades" despicable and selfish.