I read somewhere that Amadeo Bordiga, Italian Communist, said something along these lines to Stalin's face:
If the Soviet Union is the homeland of all proletarians and the revolution, then let it be governed by a joint committee of international communist parties!
This is from memory and I'm sure the wording is wrong. I thought I read the quote a few years back in this text by Loren Goldner - "Communism is the Material Human Community", however, all I find is this:
Bordiga was the last Western revolutionary who told off Stalin to his face (in 1926) as the gravedigger of the revolution and lived to tell the tale. He was ousted from the PCI in the same year and took several thousand "Bordigists" with him.
German wikipedia, Bordiga also only mentions that he called Stalin a traitor to the revolution (in 1925).
It is of course possible that the quote I remember was in an earlier version of the text and was removed because it was wrong/inaccurate. The quote is kinda awesome though and I want to know if he really said it, and in what context.