Ukip leader Nigel Farage said he backed the "basic principle" made by Enoch Powell in his notorious "rivers of blood" speech.
After hearing an extract in which Powell said the "indigenous population found themselves strangers in their own country", he told Sky News presenter Dermot Murnaghan it was "true" about large parts of England.
He said he didn't know the origin of the passage - which also talked about the country being "changed beyond recognition" and women and children denied hospital beds and school places.
But told it was from the 1968 address warning of racial violence which led to Powell being sacked from the Tory front bench and politically marginalised, he said the central premise was right.
"Is it? Well, what he was warning about is that if you have a large influx of people into an area that changes an area beyond recognition, there is tension, that basic principle is right," he said.
Asked if Powell "saw it coming", he replied: "Well no ... for different reasons, for different reasons and on a completely different scale.
"I mean when immigration was being discussed in the 60s and 70s and 80s we were talking about an annual net inflow to the country of between 30,000 and 50,000 people.
"What we have had in the last 13 years is net four million extra migrants who have come to Britain so we are dealing with something now on a scale that hitherto we couldn't even have conceived."
In 2008, Farage courted controversy by naming Powell as his political hero in an interview with Total Politics magazine and saying the country would be better today if his words had been heeded.
But Farage said he was not thinking of the ''rivers of blood'' speech when he made the choice but Powell's support of a smaller state, laws not made in Brussels and sensible border controls.
"I would never say that Powell was racist in any way at all. Had we listened to him, we would have much better race relations now than we have got," he said at the time.
Although Powell's cause was taken up at the time by right-wing Tories as well as dockers and meat porters, who went on strike demanding his reinstatement, he has since found few supporters in mainstream politics.