The rise in the fortunes of the Greens, both literally with their soaring membership, and politically with their strong opinion poll performance and inclusion in the upcoming TV debates, has led to a rise in scrutiny. Already, they have had to drop two of what they wanted to have as flagship policies (the ‘citizens’ income, and decriminalising membership of terrorist organisations) and they may have to drop more. But it’s important to understand how those policies came to be in the first place. Our election system encourages smaller parties to make unsustainable promises because it is so heavily stacked against them. Change the election system, and we would see our smaller parties change the responsibility they will take for the implications of their policies.

I have been having this debate with a student at my school who supports the Greens. Back and forth we went on the realism of a policy (citizens income) that would cost £280bn to implement, and a policy (decriminalising membership of terrorist organisations) that would increase the danger in which we live (although upholding the values of freedom of speech and association). Then, ironically just after professing that she ‘doesn’t know much about politics’ she pointed out that First-past-the-post (FPTP) means that smaller parties don’t get the opportunities or the attention necessary to show whether or not they are capable of forming a government. FPTP creates the problem of smaller parties making unrealistic claims as it gets them attention and they know there is little chance of them being accountable for them. FPTP, to this student, purely keeps power at the top, and “a vote for Greens escapes the valueless, empty coherence of those in power at the moment.”

This made me stop and think. She is right. If we had proportional representation a party such as the Greens, with 10% in opinion polls, would be designated a “major party”, and would have been so for a long time. They would have chances to form governments at each elections, and so would have to think very carefully about the deliverability of their policies. They would be less likely to argue as passionately as they did last week that because economic growth is incompatible with protecting the planet and a fulfilling personal life, we should be comfortable with policies that result in a permanent recession, with families becoming materially poorer each year. Nathalie Bennett, the Green Party leader, and Caroline Lucas, their sole MP, have said that success in life should no longer we measured in GDP, but in human values.

It is certainly radical, but also undeliverable in a democracy. However, the reason why it is radical is because when you are stuck in permanent outsider status by an election system that marginalizes small parties and makes it very difficult to get into government, you are forced to get attention by being more extreme. However much I think that the election will be distorted by UKIP promising policies that can only be delivered if we are out of Europe – which we are not, and Greens promising policies that can only be delivered if living standards fall massively short term, it would be different if we had proportional representation.

The experience of proportional representation in other countries, particularly Germany, where the Greens were in a coalition government from 1998-2005 and are often invited to form coalitions in a country where hung Parliaments are the norm, is that they are thus forced to be more realistic in their demands, because they may actually have to deliver those policies.

So let’s not complain any more about Greens and UKIP being unrealistic. We are possibly about to see UKIP get about 1 or 2 seats with over 15% of the vote and the Greens possibly getting no seats with 10%, whilst the Liberal Democrats could have 30 or more seats with about 7% of the seats. If this was the electoral system you were dealing with, what would you do?