There is certainly space in British politics for a party beyond the edge of Labour, but a left-wing alternative has yet to emerge.
It could be a blip, but the Green party's polling suggests a bright future.
The inclusion of the party would help to split the left-wing vote and harm Labour and the Lib Dems.
The party celebrates after winning a seat off the Greens in one of the safest wards in Lucas's constituency.
Nigel Farage's party would crave UK political representation to match that of the Greens.
Caroline Lucas is standing down as Green Party leader. Who is in the running to replace her?
Caroline Lucas on why she is standing aside as Green party leader
On the campaign trail with Green Party leader Caroline Lucas.
Tatchell's fate represents the activist's dilemma