Nominations for the Green Party co-leader have opened and one political commentator is picking backbencher Marama Davidson for the job

The party's relied on James Shaw as sole co-leader since early August, when Metiria Turei resigned after revealing she'd committed benefit and electoral fraud.

Now, Julie Ann-Genter, Eugenie Sage and Marama Davidson are all expected to put their names forward and members will vote in early April.