The editorial for edition 21.4 of Juncture surveys the economic, social and ecological challenges facing Europe, and traces the arguments of the leading public intellectuals who, in this issue, give prescriptions for how we can create a revived, democratised union.

The euro is an 'irreversible disaster', argues Claus Offe in our interview with him on the central theme of this edition of Juncture. 'Disastrous' in the sense that it has widened economic inequalities between its member states and deprived them of sovereignty, without a commensurate increase in democratic accountability at the supranational level. The flaws in its design have been brutally exposed by the financial crisis and its aftermath. 'Irreversible' because the costs of exit are too high and the institutional and political commitment to the project of monetary union too deep. The convulsions of the eurozone, meanwhile, have shaken the foundations of the wider European Union, raising profound questions about its democratic legitimacy, the solidarity between its citizens, and its constructive purpose.

This, then, is a crucial moment for the future of Europe, with substantial pro-European arguments being advanced on the continent – as this issue highlights – that reject the status quo and seek to save the EU from itself, by building not just a 'market Europe', but a social and democratic one too.

By contrast, much of British pro-European opinion remains moored in the past, too often falling back on a tired rhetoric and agenda of deracinated globalisation or the short-term, tactical benefits of membership of the union. Little if any of this speaks to the major challenges Europe faces, or to any compelling vision of Britain's future within it. Meanwhile, Eurosceptics are steadily assembling an alternative account of Britain's future outside Europe, based on political and trading alliances with the English-speaking 'Anglosphere' countries.

Complacency is no ally of Europe. Equally, a spirit of recalcitrance that relishes a little too much the opportunity to retreat to the nation-state and a closed politics of narrow identity in the face of crisis leads down a dead-end path. To confront the economic, social and ecological challenges facing us, we need a revived, democratised Europe. How, though, to get there?

This issue presents some of Europe's leading public intellectuals whose work seeks to address that question. The German social theorist Fritz Scharpf, for example, argues that European democracy is currently paralysed by consensus and veto, while national democracies have been undermined by the growing role of non-democratic transnational institutions in administering their economies. His solution is to allow democracy to flourish on both levels – national and EU – at the same time, even if 'European integration' loses some of its unitary appeal in the process. By Scharpf's account, democratic pro-Europeanism must embrace multilevel governance and abandon the goal of uniformity, particularly the 'negative integration' of government by pan-European legal rulings.

Tracing a similar argument, Bo Str??th suggests that the 'political abandonment of politics', driven by the EU's technocracy, has spread from the centre to member states. If Europe's institutions are to survive the crisis of legitimacy, he argues, the 'market Europe' consensus must end and a 'social Europe' must emerge. Such a Polanyian-style re-embedding of the political in the economic would require a profound renovation of Europe's institutions and national democracies. Yet, without such a fundamental restructuring, Str??th argues that a disintegration of some form or other awaits, most likely precipitated by the euro's collapse.

In his interview, Offe argues against the influential German political economist Wolfgang Streeck, who has suggested that the left should return to the nation state as the locus of emancipatory ambitions. Instead, Offe argues for a more democratic Europe with stronger forms of positive integration, for example around tax harmonisation and the transnational regulation of finance capitalism. Moreover, unlike Scharpf, he identifies in the rise of Syriza, Podemos and 'bottom-up politics' a potential agency for change across Europe.

Whether it is possible to have a democratic left-wing populism is precisely the question Yannis Stavrakakis explores. In an important piece, he seeks to rescue populism as a category from repeated denigration as excessive, irresponsible or irredeemable nationalism. He argues that Europe's economic and political elites 'identify, stigmatise and contain demands for dignity and recognition, wider participation, egalitarian justice and the radicalisation of democracy' through the branding of 'populism' as inherently nationalist, racist, xenophobic and, in the end, fascistic. As he sees it, left populism of the kind seen in Spain and Greece is an important source of political energy and represents a sustained challenge to post-democratic economic and social management in the eurozone. If these left 'populist' struggles for democracy and dignity are proven to be ultimately incompatible within Europe's current structures, Stavrakakis is surely right in arguing that 'the fate of Syriza's populism will not be our most pressing concern, academic or political'. Rather, it will be the return – wearing a mainstream face – of fascism to the continent.

The crisis in the eurozone has finally laid to rest the idea that European integration proceeds by a remorseless logic. It has starkly revealed the political forces at work in the EU, as well as its democratic deficits. But this very opening up of sharp, contested political spaces in the architecture of the union – from the board of the European Central Bank and the Eurogroup of finance ministers, to the ballot boxes of those countries revolting against austerity – gives hope that democratic politics might once again shape the future of the continent. And in this task, countries like Britain that remain outside the eurozone must have role to play, advancing arguments for substantial economic and democratic reforms to the EU as a whole, rather than marginal adjustments in its balance of power and competences. This edition of Juncture contributes the perspectives of continental public intellectuals to that agenda.

Closer to home, John Curtice uses current polling to consider the different scenarios that might play out if the latest opinion polls hold true at the general election in May. In doing so, he argues that the ensuing fracas of post-election negotiations and the real prospect of a minority government filling Downing Street are likely to provoke serious debate about Britain's electoral system and wider constitutional settlement. Not only is minority government a real possibility, but it is quite possible that the SNP – a party intent on breaking up Britain – will hold the balance of power, even though it might represent less than 5 per cent of the UK electorate. Ukip by contrast could receive twice this level of support but earn just a handful of seats. At the same time, there is no guarantee that the next prime minister will be the leader of the party with most seats.

What's more, the territorial distribution of political power also raises the prospect of Labour forming a government with SNP support that lacks a majority of seats in England. What impact would this have on English attitudes to the UK's constitutional arrangements? Lastly, it's essential to throw into the mix the changes brought about by the Fixed-term Parliaments Act, which means there is also the prospect of a 'voteless' change in government – with power moving from one party to another during the parliamentary term without an election. All of these possibilities raise different but equally serious questions for Britain's voters, politicians and constitutional thinkers.

This article appears in edition 21.4 of Juncture, IPPR's quarterly journal of politics and ideas, published by Wiley.