Unable to Launch Minecraft

I'm unable to run the launcher, despite being able to run it earlier today. I get the following error message.

 

The game failed to start for reasons unknown to us. Please try again later.
Error details: The operation requires more free disk space (299751678 B) than available (195100672 B)

 

I've deleted some 2GB of files to try and resolve the issue but still no success.