50 million is too many people for the area of land called England

In & of itself perhaps this is a non-racist reason, but in the context of his other non-racist reasons it assumes a sickening racist aura, very much of the there's enough here as it is - send the buggers back variety, especially given that it's complete bollocks, even with the present land/wealth distribution.

I'd like him to name one pure bred English person.

Every person alive in England today is pure bred English; we are the consequence of human process, diverse in culture, region, religion, ethnicity, origin & destination; we are English in our utter individual uniqueness & diversity; each & every one of us. This is the right & purpose of our Englishness; the only Englishness that matters; by choice, by love, by dint of simply being here in the first place.