I understand that ‘a debate in process’ is a set phrase but apparently ‘a debate in progress’ is a strong collocation too. Is there any difference between the two?
I had to think about this for while. At first I thought the two words could be used interchangeably. I think if either word were used, most people would not notice the difference. I think ten seconds later most people would not even know which word was used.
However, I think progress is more correct, although I can’t say why.
In the context of a debate, probably the vast majority of people have never used either one. I’m not sure if I’ve even heard it before. In other contexts it’s not too unusual.