The rest of the country subsidises Auckland and provides it with the wealth to exist.
This is not a view unique to Damien. Michael Cullen once said:
Auckland now sits atop the nation like a great crushing weight
I think it is commendable Damien shares his views with us. he is obviously positioning to become Finance Minister.
Incidentally a report in 2006 concluded Auckland sends $3.8 billion more tax to Wellington than it receives back in spending.