Okay, this was simple in the end! Eclipse performs an auto-login to the Google account, unfortunately I created the Eclipse project whilst being logged in to one Google account and then tried to specify the application name afterwards.
You'll see in the bottom-right (or bottom-left in some versions) a Google icon with the name of the user that you are logged in as. If that's not the account where your application is defined, then simply logout of that account, then login as the correct Google account.
Now there's no error :-)