Labour's yet to rule out the Green Party's plan to establish a publicly-owned supermarket chain, saying it has its own policy on breaking up the duopoly in New Zealand.

The party says it'll buy 120 Woolworths, Pak'nSave, New World and Four Square stores.

Labour's yet to rule out the Green Party's plan to establish a publicly-owned supermarket chain, saying it has its own policy on breaking up the duopoly in New Zealand.