A major step forward for the Greens?

There is speculation that the Green Party could win overall control of a council for the first time

And this makes it a good time to look again at the role of minor parties in UK politics.

A refresher on the role of minor parties...

British party politics in the post war era could easily be slotted into Giovanni Sartori's classification of party systems as one of two-partyism - with the apotheosis of this being the 1951 election, where the Tories and Labour garnered nearly 97% of the vote.

Post 1970 (where the nationalists won their first seat at Westminster) we have seen a drift via a two and a half party system period to one of multi-partyism - despite an apparent blip in 2017, an election the constitutional scholar Vernon Bogdanor described as an "aberration" given that it was the "Brexit election".

No commentator worth their salt is predicting a breaking of the mould, a radical overhaul of the established order, or even the seismic shift witnessed in Germany with the AfD, or the Lega Nord in Italy or the Sweden Democrats. But there is no doubt that the big two in the UK (and this is without contemplating if the Lib Dems should be re-categorised as a minor party) will continue to cede ground to minor parties in the near future.

So what is their role in modern party politics?

• The most obvious role to consider is that of representation. Generally, minor parties in democratic systems seek to fill an "ideological space", usually to the left or right of established parties. With the post war consensus in effect in British politics from 1945 onwards one would expect minor parties to take hold away from the centre. On the contrary, the Communist Party of Great Britain never gained more than a few thousand members, and extremist far right parties were almost unheard of. In recent times as parties have converged around a new consensus, slightly to the right of the old one, a similar picture can be seen. In the left, the Scottish Socialist Party had some brief traction in the early noughties, and on the right the BNP, and other fascist offshoots like Britain First, have had their time in the sun, but it is mainly minor parties who have targeted "policy vacuums" that have been more successful. Here two examples stand out. According to figures from the House of Commons Library, the SNP (who have the pursuit of full independence for Scotland at its core) now have 125,000 members, putting them ahead of the Conservative Party. And UKIP, led by arguably one of the most successful politicians of the modern era in Nigel Farage not only sucked in thousands of new members who were die hard Eurosceptics dissatisfied with the inability of the traditional big two to resist the erosion of British sovereignty, but also in the summer of 2016 it attracted the support in the referendum of millions of voters most affected by the post 2010 austerity measures enacted as a response to the Great Financial Crash in 2007/8. And there are the Greens, whose membership doubled in the run up to the 2015 election, outnumbering both the Lib Dems and UKIP at around the 50,000 mark.

• Since parties can be differentiated from pressure groups in that they put forward candidates and therefore seek to win electoral office, the significance of the electoral function is worth considering: It is often said that the single member simple plurality electoral systems tend to mitigate against minor parties (in political science this can be supplemented by evidence of Duverger's Law). But this is not always the case. It depends on whether voters, and indeed potential voters, are evenly spread across number of voting districts or concentrated in pockets. The combined impact of the SNP and UKIP stand out here. In 2015 they received over 5 million votes. SNP managed to convert their 50% of the vote in Scotland into 95% of seats in the nation. UKIP, meanwhile, won just one seat for their 3.8 million votes. Without a change to the electoral system at Westminster it is unlikely the picture will change for minor parties. Because of the fear among the electorate of wasting their vote, the press rarely give the 400-500 or so minor parties and independents any coverage, so there is a double whammy. Yes, many of the registered parties at General Election time are attention seeking eccentrics, but many are pushing important causes - they may want to further a local issue, unseat an unpopular incumbent or have an anti-mainstream agenda. In the first group Dr Richard Taylor who won in 2001 and re-elected in 2005 against the closure of a local hospital's A&E Dept. Or take the case of the Women's Equality Party in 2017 that put a candidate up against, among others, Philip Davies MP in a Yorkshire constituency, targeting him because of a perceived misogynist agenda. The victory of ex-BBC news reporter Martin Bell in 1997 over corruption tainted Neil Hamilton in Tatton falls into the second category. And the BNP have an obvious "Britain is broken" agenda and have gained success at local government level (over 50 councillors in 2009), regional (a seat in the London Assembly in 2008) and European elections (2 MEPs in 2009 and nearly a million votes). The vast bulk of minor party candidates at national elections, however, are fringe with a capital "f", and there have been steps by the Electoral Commission to exclude several of them - not many will shed a tear, however, over the fact that the “Mongolian Barbecue Great Place to Party” was not allowed a place on the ballot after 1997.

• There is a point of view that minor parties have come in from the cold and are no longer prevented from influencing the policy agenda. Either Either they have been part of the Westminster governing apparatus itself, such as in the Lib-Lab pact of the late 70s, the UUP support for Major in the early 90s, or the tail wagging the dog of the DUP today in May's administration. There was undoubtedly a greening of British party politics in the late 90s and early 00s, and there is ongoing debate about the threat of the Greens here. Less controversially is the significance of the impact of UKIP on the political scene. The party shifted from being a thorn in the side of Tory party leaders to being instrumental in taking the country on a path to Brexit. Away from Westminster, we have to think about the impact of minor party votes in creating increasing numbers of councils under no overall control, and the sway the Greens have had on council environmental policies. Then there is the combined effect of Labour's devolution package in terms of new legislatures alongside new forms of election systems. Most dramatically, the nationalists have held power in Scotland for over 10 years, and while it is possible to argue that under Scottish Labour Holyrood was already ploughing its own tartan furrow, the SNP have a record in government that deviates markedly from what has happened south of the border: university tuition fees scrapped; a massive extension of free child care; free prescriptions; a ban on fracking. And let's not get started on how close many thought the independence vote was going to be.

So, according to the Guardian this week, the Greens could grab as many as five extra seats ad take control of Mid Suffolk district council.

One to watch in today's election!!