“How did you go bankrupt?” asks a character in the Ernest Hemingway novel The Sun Also Rises. “Two ways”, comes the reply: “Gradually, and then suddenly.”

On Thursday the people of Peterborough go to the polls. Will they be bookending two weeks in which our two-party system suddenly went bankrupt? The Brexit Party is odds on to win the by-election. They could be surmounting the first-past-the-post barrier just as Labour did 100 years ago.

The Tory/Labour duopoly has, of course, been written off many times and always seems to endure. But nothing, as Echo and the Bunnymen sang, lasts forever. Are we at a momentous political tipping point?

The last week or so has seen a tumult of the evident crisis. Over the weekend, news from the continent was that Andrea Nahles, the soft left Ed Milibandesque leader of the German SPD had resigned, unable to turn her party’s ailing fortunes round. At the same time a poll in Germany has put the Greens ahead of the CDU for the first time ever. The crises is Western in nature, not just Westminster. But back in Britain, both Paul Mason and David Blunkett set their cross-hairs on Labour Leaders courtiers, not Corbyn himself. This is just displacement activity for the real questions about how we reconcile the intensely difficult contradictions between communitarianism and cosmopolitanism, national interests and global imperatives, turbo-consumption and sustainability.

The previous week, the Euro-elections were won by a party that has only one policy. The two ‘main parties’ secured only 23% of the vote between them. In the process 41% of Labour members voted for parties other than Labour. With a self-reported turnout of 90%, that means almost 200k Labour members broke the party’s rules. Alastair Campbell was expelled for declaring that he voted Lib Dem, triggering a backlash – #expelmetoo – on social media. At the end of the week the polls of Westminster voting intentions put either the Lib Dems first on 24% or the Brexit Party first on 26%. Whatever is happening – we’re not in Kansas anymore.

This is just the surface swell of deeper undercurrents that are dislodging ancient political tectonic plates. Today class, constitution, culture and climate vie in ways that puts the old left/right divide on a spectrum somewhere between questionable and meaningless. It challenges us not just to reinvent representative democracy but come up with new forms of collective decision making that are fit for the always-on, always-connected networked society we live in.

Ultimately the crisis forces us to reconsider our own role in the changes that have to be made. We search for a hero that will save us – a Macron, a Blair or a Corbyn. But following someone and taking orders neither fits the culture of the day, nor is a recipe for meeting the fiendishly complicated challenges we face. There is no-one but us, the people, and the internet – so what are we going to do other than embrace the complexity?

We have a multi-party reality shoe-horned into a two-party system. Of course, the binary nature of our electoral system and adversarial political structures can force some voters back into a least worst option choice – but that is all about making people do what, given a free hand, they wouldn’t otherwise do. Instead of a ‘protest vote’ where people experience the joy of voting for who they actually want, they will be told to get serious, and back either socialism – Labour – or barbarism – the Tories. This politics is so nakedly instrumental and self-serving, it doesn’t matter that its unfair or ineffective – as long as the ‘right people’ – ‘us’ – win. Fidelity to the machine is everything. In this vein, perhaps the most depressing reports in recent days concerned Labour’s treatment of a Corbyn aide over sexual harassment claims. The Times reported that a recommendation from party officials to suspend David Prescott’s membership of the party had been rejected by the leaders office, raising concerns from amongst Labour’s own MPs about the possibility of “political interference”.

Zombie-like politics can rumble on, but even if it does, it will be so deeply dysfunctional that it will create the conditions for change, for better or worse. While the form change takes is unclear, what we do know is that reluctant and cajoled voters and party members are no basis for the transformational project our country needs.

And we know the vice-like grip of Labourism is being prised open. Culture is trumping tribalism. People are so restless and quick to swarm from one resting place to another that many are flocking back to the Liberal Democrats who themselves looked dead just a few months ago. The worry here though is that this is yet another sugar rush swarm that could be over as quickly as you can say Change UK. Cablemania anyone?

In all this there is no comfortable ground to stand on – nor any going back. The forces and political ideas that the created the crisis are incapable of finding its solutions. The issue is no longer who can form a single party government for five years, but who can win this particular vote, assemble this or that collation, represent fluid and fleeting interest groups, who gets the culture of pluralism and wants to create the spaces to listen, learn, negotiate and adapt. It means not just proportional representation but an end to the Whip system, the relocation of Parliament into a modern building, radical devolution and citizens assemblies – for starters.

This country has failed to return a stable government with a working majority since 2005. The odds on that trend reversing are dropping day by day. In Peterborough on Thursday the odds might fall off a cliff. The choice is simply a new politics or a new authoritarianism. Will this be the moment when the choice could no longer be dodged?