21/05/2014 13:06 BST | Updated 21/07/2014 06:59 BST

European Elections 2014: What's Firing the Green Surge

It's only an opinion poll, a lot's going to depend on the results in individual regions, it's still all to play for - all of those old electoral sayings hold true, but nonetheless Green Party workers are going into the final sprint of the European election campaign with a spring in their step, following a YouGov poll for the Sun that put our vote on 12%, enough to win six MEP seats in England, plus one in Scotland.

That would treble our representation in the European parliament, sending four new MEPs to join Jean Lambert and Keith Taylor, the reps for London and the South East regions, where we've held seats since the election went proportional in 1999. It's a figure that's even approaching the heady heights of 1989, when the Greens won 15% of the national vote, although not a single seat in those pre-PR days.

It's notable too that this is 50% of the poll result for Ukip - despite the fact that the Green Party couldn't have had 5% of the blanket coverage that non-Westminster party has received.

I'm often asked by journalists: where are the votes coming from? The answer to that very simple: just about everywhere.

There's certainly plenty of former Liberal Democrat voters (and members) who've come over to us: often they cite the obvious issues of tuition fees, nuclear power and nuclear weapons, but I think it was one of our Green councillors in Solihull, a former Lib Dem, who put it best: "You represent my values; the Lib Dems no longer do."

But by numbers I suspect the largest group (because there were a lot more to start off with), are former Labour voters, or dissatisfied Labour-inclined voters. Indeed, one commentator has just described us as "the real threat to Labour". They look at the fact that we're calling for real change in a society, to an economic model that works for the common good, not just for the good of the few, while the three largest parties, Labour included, are basically calling for business-as-usual, with a few rhetorical flourishes and conscience-sops here and there.

On specific policies, they love the fact we're calling for the railways to be returned to public hands (and that Green MP Caroline Lucas has a private members' bill now before parliament to do just that). They understand that our call to make the minimum wage a living wage - the simple statement that if you work full-time you should earn enough money to live on - is both more powerful, and effective, than Ed Miliband's complicated formulae and offer to companies of tax breaks if they do the right thing.

And they above all understand that we are saying the poor, the disadvantaged, the young, should not be made to continue to pay for the fraud, mistakes and excesses of the bankers with continuing austerity and cuts to the essentials of those who need our help.

There are also quite a few former Tory voters coming our way. One obvious area is fracking: the Green Party's position as the only mainstream party absolutely opposed to extreme energy (also including coal bed methane and underground coal gasification - technologies that should have no place in a warming world) is attracting many, as the Guardian found.

Beyond that, however, our resistance to building on the greenbelt is also attracting votes, as is the Green position, both in Britain and Europe, of demanding (and getting) real action to rein in the bankers: there's many voters right across the political spectrum rightly gravely concerned about the failure to tackle the "too big to fail" problem, let alone deal with the apparent "too big for jail" issue.

The final new group is one that I wouldn't have predicted, although I'm very pleased about it. That's traditional non-voters, people telling me they've "never" voted, or "not for decades". Understandably suspicious of electoral politics, fed up with three Identikit large parties, they actively abstained, but the rise of Ukip has led them, as one put it to me to decide "we've got to vote for you as a counterweight". They've particularly noted that we're the only party standing up to Ukip populism, rather than trying to outdo it, on issues ranging from immigration to climate change.

And then of course, I shouldn't forget the long-term loyal Green voters, who've been there all along. For many climate change, the clear and present is the big issue, but they're also concerned about protecting our wildlife and biodiversity, our ancient forests and fragile seas, want real progress on animal protection issues.

So our voters' motivations are many and varied. But what they do know is that this is a proportional representation election in which ever vote counts - and they're determined that theirs does count for real change, not more of the same.