Zack Polanski speaking at the launch of the Wales Green Party election campaign in Cardiff. Photo by Ben Birchall/ PA via Alamy Could we soon say goodbye to the Green Party of England and Wales? A senior source within the Welsh Green Party has told the New Statesman that a split from Zack Polanski’s party “is not only desirable but also inevitable”. If the party secures its projected share of seats in the Senedd later this week, the process could accelerate. The Green Party once operated across the entire UK. But in 1990, the Scottish Greens broke away to form their own party, leaving the Green Party of England and Wales. For now, the party’s focus remains firmly on the Senedd elections. Just a year ago, it was aiming to win a single seat – contested by its leader, Anthony Slaughter, who is standing in the Senedd seat Caerdydd Penarth, which maps onto Cardiff South and Penarth, the former constituency of James Callaghan. But expectations have shifted.…