Zack Polanski, the Green Party deputy who is the current frontrunner in the leadership raceZack Polanski has become something of an internet phenomenon of late.Despite being the deputy Green leader since 2022 and a member of the London Assembly since 2021, he was definitely not among the most well-known politicians, even within his own party.But something changed in May when, after years of membership, he announced he was running to lead the Greens on a socialist ticket, as an “eco-populist”.Although the party has not officially declared how many members it has, leaked figures suggest the membership grew by 8,000 in the weeks after his declaration – taking them to at least 65,000.Rumours of potential defections from disillusioned Labour MPs have even been swirling, although any concrete details have been kept under wraps.