Green Party targetting disenchanted Labour voters

I saw this on on Whale Oil’s blog and thought it was worth commnting on. At the least it is a clear campaign to win voters off Labour. At worst it is a declarion of no confidence in Goff from the Greens.

I can’t recall too many examples of an small opposition party so directly targeting their ideological ally previously. I wonder how long these ads will run for, and will they be just online or might we see some billboards also?