This by @NadineElEnany is :

"Britain’s borders, articulated and policed via immigration laws, maintain the global racial order established by colonialism, whereby colonised peoples are dispossessed of land and resources..." https://manchesteruniversitypress.co.uk/articles/britain-as-the-spoils-of-empire/

"...They also maintain Britain as a racially and colonially configured space in which the racialised poor are subject to the operation of internal borders and are disproportionately vulnerable to street and state racial terror..."

"... Britain is thus not only bordered, but also racially and colonially ordered, through the operation of immigration control."

Need to order this book pronto

On the 1981 immigration act

"The 1981 Act did not therefore signify an end to British colonialism but was itself a colonial manoeuvre. It was an act of appropriation, a final seizure of the wealth and infrastructure secured through centuries of colonial conquest"

Understanding Britain as a contemporary colonial space serves to partially collapse the distinction between settler and non-settler colonial contexts... the border around the spoils of British colonial conquest via immigration law amounts to an unredressed act of colonial theft