It was a remarkable and emotional sight. It was meaningful, in a way that went far beyond the events of today and spoke to something far deeper in our national character. Tory MPs Anna Soubry, Heidi Allen and Sarah Wollaston entered the Commons, stood for a moment at the floor of the House, and then turned right instead of left. They were no longer on the government benches. Instead they walked up to their new colleagues in The Independent Group, who now number eight after a further Labour defection overnight, and sat down alongside them. Soubry shook hands with Chuka Umunna. Allen sat next to Luciana Berger. Smiles all round. Selfies taken.

It wasn't just remarkable for the sight of former political opponents sitting together, or for its news value. It was remarkable because of what it represented. It stood against the poison of the age: the constant toxic tribalism that has infected our political debate. It wasn't just that they sat together. It was that they smiled together. They were getting on. Something important was happening. This was a cultural moment as well as a political moment.

No-one really knows what happens next. Part of the problem with our political culture is that pundits are tasked with demonstrating rock-hard confidence in their predictions, even when the historic circumstances we find ourselves in are so changeable and chaotic that no prediction could possibly be made with any confidence.

The political muscle-memory in this country is of the SDP, who split with Labour in the 80s and, according to legend, handed Margaret Thatcher an unbroken decade in power. In reality, the evidence is open to interpretation. Some studies suggest that the SDP acted as a safety-zone for alienated Labour voters, giving them a home without drifting to the Conservatives. It's a more complex picture than people think, but regardless – that's the lesson most absorbed.

True or not, these are different times. Technology, ideology and the fundamental economic conditions in which we operate have changed. Events are constantly surprising us, from the financial crisis, to Brexit, to Trump, to the 2017 election result. Things are not as they were before. Historical lessons do not offer the guide they once did.

The signs are positive. A YouGov poll for the Times today found extraordinary levels of support for the new group, especially given it does not actually exist as a party yet, let alone have a policy. It put them on 14%, next to Labour's 26% and the Tories' 38%.

It is perfectly realistic to imagine that within a month or two, they could have 30 or so MPs. Certainly there are enough alienated figures in both of the main parties for those kinds of numbers. They have already overtaken the DUP. Once they get past 35, they overtake the SNP as the third party and get a guaranteed place asking questions at PMQs.

It would start with the other MPs facing deselection battles, either from Brexit hardliners in the Conservatives or Momentum activists in Labour, and spread from there. Speaking on Sky News this afternoon, Labour MP Jess Phillips was entirely open about how tempted she was. "I was born Labour and I felt like I'd die Labour," she said, "but when I listen to my colleagues [like Berger, Umunna etc] speaking I find it very hard to disagree with a lot of what they were saying."

During PMQs today, the system was shell shocked and speechless. There was not a single mention of the tectonic plates shifting underneath their feet. Neither leader could mention it because it affected them both equally. But away from the cameras, the knives were already out. Both parties reacted in a way that validated the arguments of those departing them, because they don't know how else to behave.

Labour sources were branding the new group "a Tory-Establishment Coalition". Jeremy Corbyn very publicly pushed forward with plans to give the voters the right to petition to recall their MPs if they shift party – a clear signal that he is more in attack than listening mode.

His statement on Monday, after the original seven departed, was predictably and completely tone deaf. "I am disappointed that these MPs have felt unable to continue to work together for the Labour policies that inspired millions at the last election and saw us increase our vote by the largest share since 1945," he said. He didn't even mention anti-semitism.

Today, his friend and ally Chris Williamson spoke to the media and suggested many of the complaints about anti-semitism were "malicious" and invented to damage the Labour leader. It was despicable. And also completely normal. That is the true horror of the situation.

May's response to the three defections this morning was, in its own Tory way, almost identical. "The UK's membership of the EU has been a source of disagreement both in our party and our country for a long time. Ending that membership after four decades was never going to be easy. But by delivering on our manifesto commitment and implementing the decision of the British people we are doing the right thing for our country. And in doing so, we can move forward together towards a brighter future."

Nothing had changed. May is simply incapable of thinking again, or adapting to circumstances, or speaking honestly, or with even a modicum of emotional normalcy. The two main parties are led by such dreary unimaginative machines. They have nothing new to offer, except drudging persistence, half-truth, smears and innuendo. The Independent Group's greatest advantage is that their opponents are so useless. But then, if they weren't, they'd still sitting alongside them.

This could very easily piffle-out into nothing, just a little rump of MPs who acted too soon and were unable to congeal into something positive once their act of rebellion had subsided. But the truth is that we live in remarkable and fast changing times. The two main parties are both zombified and poisoned. The moment is primed for something to truly shake up the way this country does politics. This could be it.

Ian Dunt is editor of and the author of Brexit: What The Hell Happens Now?

The opinions in's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners.