Last night’s election in the UK marked a seismic shift in British politics and in the state of the union. I suspect we will deal with the fallout for many years.

There is of course, the micro-analysis – yes, it was assumed disillusioned Lib Dems would go to Labour, but it looks like they went Conservative instead, perhaps fearful at the prospect of a Labour-SNP deal. But here are some thoughts on the larger pieces, and the fundamental shifts we will see in coming years.

1) At the ballot box, people voted with their identities. For all the talk during the campaign, what actually mattered were not policies or the economy, it was the way in which British people see ourselves. Scottish, working-class, ethnic minority, northern, welcoming, english. These are all loaded terms in a class-divided UK.

Scotland clearly sees itself very differently to England. With the SNP taking 56 of the 59 seats, voters chose an open, anti-austerity, progressive message of a vibrant, independent Scotland. A Scotland with a future in the EU. A Scotland that rejects the parochial, small-mindedness with which it stereotypes England.

And indeed, how far from the truth is that stereotype? In the majority of Labour seats, the runner-up was UKIP. Over the last decade, Labour has bled votes from its white, working-class base, to UKIP. Fearful of change, affected by rising unemployment, seeing their communities modernize around them, they turned to the party appealing to their fears – UKIP. There is not so much a political spectrum with left and right at opposite ends, as a full circle where they meet at the top.

Towards the end of the campaign, Cameron’s message was fairly negative, invoking fear of separatists, and the spectre of a weak Labour government held ransom by a practically foreign leader. He supported ‘English votes for England’ – a phrase that evokes Little England and an insular nation. Over the past year, Cameron has seen his greatest threat coming from his right, in the form of UKIP. In response, and to appease his own restless backbench, he shifted further right on a number of key areas. There were themes of ‘others’, who were out to steal your benefits, and of scroungers and immigrants competing for finite resources.

2) This isn’t about Scotland any more. It’s not about Westminster granting small tokens of autonomy to the fringes, to slow the creep of separation. The UK needs to see major constitutional and governance change. It’s clear that with Wales and Scotland stretching in such a very different direction to England, the UK needs to get to grips with federalism. Nothing less will keep the Union together. Getting to grips is less about the technical policies and workings of federalism, as it is about the mindset of British people. Federalism would be a major cultural shift, one not understood or even within our conceptual framework of our country.

But without a holistic, systemic overhaul of our governance, considering the four component parts of the Union – Wales, England, Scotland and Northern Ireland – we will likely see a second Scottish referendum in the next five years.

3) A second Scottish referendum is made more likely by the coming EU referendum. To ward off UKIP on his right, and settle his significant Eurosceptic caucus, Cameron promised a yes/no referendum on EU membership. While Cameron does not want to preside over a Brexit (British exit from the EU), he does want significant reform of the way the EU functions. The success of his efforts to reform the EU will determine his narrative around the referendum, and its timing.

If Britain votes to leave the EU, this would almost certainly trigger a Scottish referendum, as Scotland firmly wants to stay in Europe.

4) This could be Cameron’s moment. Or it could sink him. There are two weighty, career-defining issues on the table. How he handles them will shape historians’ view of his time in office.

Part Two: Where does the progressive left go now?…..