Does political correctness shut down debate?

'Political Correctness is a form of mind control to control free speech, to undermine public opinion, to weaken the defences of democracy and to re-educate schoolchildren; it is a well doented Communist subversion procedure.' When anyone in the United Kingdom talks about immigration we seem to get labelled 'racist' or 'bigot' was this just labour making the opposition to their polices politically incorrect while they're polices where political correct? It seemed anyone who debated about the mess of immigration would be shouted down. What do you think?