Why was the outcome for the Green Party rather poor at the May 5th elections 2016 in Britain? My guess: a lot of green voters wanted to support Jeremy Corbyn by voting for Labour.
Unfortunately this vote was for Labour, and not for Jeremy
It looks like Labour did well. Many elected Labour Councillors will not support Corbyn, and the old temptation will slowly unfold in the next years:
Labour will try to gain votes from Liberal Democrats, Conservative and even UKIP by
adapting their policies towards them - and this will actually weaken Jeremy Corbyn's position.
For the future I can foresee, that the Green Party will struggle growing and with getting support, as many green voters will continue to support Corbyn
and vote for Labour.
By trying to reconcile the right and left fractions and discrepancies of their members, the Labour party will become weak and loose members to the right.
After all, Labour is a big established party ship, and does not quickly
change it's course. And the corruptive force of power is affecting all big parties...
Conclusion: if you want to support Jeremy Corbyn's position in the Labour Party, vote Green.
A strong but small (small is beautiful!) Green
Party is the best motivation for Labour to try to get the Green votes back by adapting some green policies.
Here is a link to an article I wrote for 2015
Ralph Nimmann ("Rainbowralph"), Hebden Bridge, 7th of May 2016