True, it’s not easy being Green. When you're a small party in a political system set up to favour the larger parties, you can never really win - certainly not without proportional representation.

Geoffrey Lean says the Green party has "done damage" to the environmental cause by conflating environmentalism with leftism. It should, he says, either back off from the "Green" label or move towards the centre. So in such a tightly-packed political landscape, is there any real need for the Green Party we currently have? To that I give an unequivocal yes.

For years I was told, both politely and not-so-politely, that the Greens were irrelevant because they were a single issue party (ie the environment). Then, later, they became irrelevant because they picked up the mantle of “left-wing opposition” and shed centre-right supporters along the way. It’s a Catch-22: if we espouse more radical left-wing policies, we're held in contempt by centrist environmentalists, but if we focus on green policies, we're you're dismissed as too narrow.

But this is nothing new. The Greens have long held a radical left-wing agenda, evident in their policies from defence through education to the economy and health. For me it is a sign of progress that the election at least made everyone more aware of the Green Party’s left-wing policies. When I worked there, we wanted to move away from being an environmental pressure group and into the realm of “grown-up politics”. How could the party expect to get elected if they were solely interested in green issues to the exclusion of all else? It would make MP surgeries a surreal experience. “I have an issue with my neighbour.” Awkward silence. "This neighbour... are they responsible at all for global climate change?”

So where now for the Greens? Well, whichever way the party spins it, it is a shame that only one MP was returned. Fortunately that MP is Caroline Lucas. Many people within the party long for Caroline to return as leader, but this was arguably impossible for her to do pre-election. Now, however, there is hope that she will return. If she does, then expect to see a huge upswing in interest from disaffected Labour and the few remaining Lib Dems.

The ground once occupied by Labour is now rapidly being seized by the SNP, who have proclaimed themselves the “real and effective opposition” to the Tories. I find it politically disturbing that a party so clearly uncomfortable with being part of the UK now sits in Westminster making decisions that will affect English people. It’s a little like throwing a shindig only to find that the people invited who vehemently didn’t want to attend have eaten all of the sausage rolls and are playing the Proclaimers at full volume in the lounge.

Of course, a large part of the SNP's success is down to Nicola Sturgeon's huge charisma, which she used to good effect in the pre-election debates. She was what the Greens should have and could have been. In her sharp, tailored suits, she stood out in a sea of grey and green, a confident general issuing a call to arms.

Indeed, the Greens' message was somewhat drowned out by the press fervour over the SNP leader. This was a pity, because the Living Wage is a Green idea, as is taking the railways back into public ownership. Who isn't sick of ever-shrinking trains and huge fare hikes?

The Green Party are a necessary political force, not least for holding other parties to account - be that the Conservatives, Labour, Lib Dems, or Ukip. That is not to say I agreed with all their policies; I did not. But voters deserve an electoral choice. We may not agree with each other's political priorities but we should respect their right to exist .

If the Greens are to kick on and add to their number in parliament in 2020, they need a leader capable of communicating their message. And with all due respect to Natalie Bennett, they should look no further than their democratically elected member for Brighton and Hove.

Zoe Hall worked as a Green Party press officer for three years. She now works in PR.