>>Chinese are concerned about immigration of people who come there to exploit the welfare state (even if it is actually rather non-existent).
That's literally the same concern everywhere. Polish people are concerned about immigrants coming there to claim their benefits, even though the immigration is literally non-existent, and Polish welfare pays something like $60/week if you are unemployed so it's not exactly something people would come here for. It's just people being fearful of issues that don't exist.
Some concerns are more justified than others. Looking at Calais jungle, the concern about continued and increasing immigration to UK is fearful of issues that actually do exist.
Immigrants hiding in trucks in Calais to get to Dover are not going to care if the land on the other side of the channel is flying the EU flag or not. They are doing it illegally so they will continue doing it anyway.
That's literally the same concern everywhere. Polish people are concerned about immigrants coming there to claim their benefits, even though the immigration is literally non-existent, and Polish welfare pays something like $60/week if you are unemployed so it's not exactly something people would come here for. It's just people being fearful of issues that don't exist.