Migration to the United Kingdom was a big part of postcolonialism. It is important because without the migration postcolonial voices would have been more timid and less likely to speak out. In the process of witnessing others similar to them sharing their experience, in London of all places, it encouraged the spread of postcolonialism.
There were a few key reasons for why people were migrating. They are called push and pull factors. The primary motivating pull factor, was the post-war labor shortage that England was experiencing at the time. This provided many an opportunity to find work and hope for a new life in England. Those migrating simply saw England as a better opportunity than where they were at.
With the increase in migration there was a lot of tension created between the citizens. This was primarily because those that were previously subjects of the British Empire were suddenly being made equal with everyone who had been a part of the empire from before. This caused a reconsideration of what British national identity really was. How did the new migrants fit in with the rest of society? Out of the tension there were further surges from postcolonial writing, especially by prominent authors from prior colonies of England. Some of the authors were Bennett, Soyinka, Kamau (then Edward), Brathwaite, and Chinua Achebe. With these many diverse voices they transformed London from its previous staunch, consistent, and calculated state to a more welcoming and diverse city, which was further impactful to other regions looking to them as an example.