A hundred years ago they had a different response to people who betrayed their own nations and imported foreigners to seize political power from the native inhabitants.
They called it treason and a man would see the gallows for it. Not an indignant essay in the weekly paper about how shameful it was. They called it high treason and a man would stand on the gallows for crimes of this magnitude.
Make no mistake, this strategy of Labor in Britain constitutes the very worst sort of treason against one's native land that is imaginable. It is the definition of treason itself.