From Stuff.Co.NZ (although not corroborated by another source, admittedly):

A discrete diplomatic lunch, a free trip to Washington and assurance of “assistance” from the US Embassy in Wellington have been used to blunt the Green Party’s “radical positions on many issues”, a leaked American diplomatic cable reveals.

The Americans seduced Green co-leaders Metiria Turei and Russel Norman, the latter with a free trip to Washington, and managed, over a lunch, to get a commitment from list MP Kennedy Graham “to turn (to the embassy) for any assistance he made need in the future…”

On the July 15, 2009, lunch between Graham and US mission head David Keegan, the cable said:

“The overarching purpose of the July 15 lunch was to establish the beginnings of a warm and respectful relationship with Graham,” Keegan cabled home.

“By lunch’s end, an open dialogue and a mature relationship with Graham going forward were highly probable.”

He said Graham displayed an “extensive knowledge and understanding of global affairs”, was “an evident multi-lateralist” and a “moderating influence on his frequently radical party.”