This is a moment of high danger for the Labour and Liberal Democrat parties, but also of opportunity. The voters returned 306 Conservative MPs, representing a 36 per cent share of the vote. They have returned 343 non-Conservative MPs, representing 64 per cent of the voters. Most of the non-Conservative MPs are opposed to the Tories. Even if the Lib Dem leaders and some of their MPs are not opposed, their members certainly are. Why, then, is it assumed that a Conservative government is the only one which has any legitimacy?

The Tories and their many apologists in the media are confusing a long-standing sense of entitlement to govern with the issue of parliamentary legitimacy. Britain obviously has a parliamentary not a presidential system. As Professor Vernon Bogdanor, David Cameron's old tutor at Oxford, writes on page 22: "The fundamental principle of parliamentary government is that parliament decides who should govern."

A sense of entitlement lies deep in the Tories' DNA: in their own self-image, they remain the natural party of government, whose historic role has been to rescue the nation from chaos and misrule.

Long before, and throughout the campaign, David Cameron and George Osborne behaved as if they thought they were born to rule, that it was their turn. Certainly the circumstances could not have been more propitious for them: the first great economic crisis of globalisation, the worst recession since the 1930s, an exhausted government tarnished by the failures of the Blair-Brown years, an un­popular Prime Minister who could not command even the unity of his own cabinet, and the support of a disgracefully partisan press and assorted business leaders. All of this as well as a campaign funded by the spending power of the non-dom, billionaire Conservative Party deputy chairman, Michael Ashcroft.

And yet, Mr Cameron still could not win a small majority, hence the desperate concessions that have been offered to the Lib Dems in an attempt to draw them into coalition in the "national interest". However, there are many on the right of the Conservative Party who are deeply opposed to coalition of any kind with the Lib Dems, as well as to reform of the voting system. They will not forgive Mr Cameron for his soft-focused modernism or his failure to win the "unlosable election"; the slow-burning civil war in the Tory party is about to burst into flames once again.

This magazine has been absolutely clear in its position. We are committed to radical constitutional and electoral reform as outlined in innumerable
editorials, and to a realignment of progressive politics. Proportional electoral systems tend to be more successful in delivering the social-democratic ends that we support. A new voting system would also help to disrupt the political-media nexus, and diminish the influence of the forces of conservatism represented by the City, the Murdoch family and other press tycoons.

When it was clear that Labour could not win alone on 6 May, we urged our readers to vote tactically to prevent a Conservative victory. We thought a hung parliament would offer opportunity for renewal and for new alliances to be formed. In the event, we have a hung parliament, but the outcome is more confused and less optimistic than we had hoped: we would have liked to see more Liberal Democrat MPs, in order to cement a progressive majority in the Commons.

So what now? For all the excitement on the centre left about this hung parliament - which we have long predicted, against the groupthink that dominates so much of our political discourse - the chances of a rainbow coalition of Labour, the Lib Dems and various nationalist parties holding together for more than a few months, if it came to pass, seem remote. Already Labour MPs in Scotland are expressing grave misgivings about allying themselves with their implacable enemies in the Scottish National Party. The country is facing a period of necessary fiscal retrenchment. Would the SNP and various Ulster MPs vote for punitive cuts in public spending that would adversely affect the state-dependent nations of Scotland, Wales and Northern Ireland? Unlikely.

Nor is it likely that many Labour MPs would vote for the introduction of a more proportional voting system. First-past- the-post serves them very well, thank you, delivering safe seats in Labour strongholds in the north of England and Scotland. There is the danger, too, that the electorate would punish Labour and the Lib Dems at the second general election that will surely follow before the end of the year. When a jury is hung, the judge orders a retrial. It will be the same with this parliament.

Many Old Labour operators, such as David Blunkett and John Reid, are fearful that the Tories would win a substantial majority at any second election, especially if any rainbow coalition had collapsed in discord, thus condemning Labour to the wilderness for a generation. This would also allow Mr Cameron to reform parliament in a way that would reduce the number of MPs from outside England and increase the likelihood of the break-up of the Union. That way would lie permanent Tory rule in a Eurosceptic, Atlanticist England: a kind of John Redwood Utopia of low taxation, free trade and closed borders.

There was much to admire in the way Gordon Brown announced his resignation on the afternoon of 10 May: the move was audacious, dramatic and mischievous. It succeeded in panicking the Conservatives into making hasty concessions on voting reform. Nick Clegg may have had a disappointing final week of campaigning - he became overconfident, his message was inconsistent - but he must be delighted to be in such a position of power and responsibility - and to have hastened the departure of Mr Brown.

Despite the ebbing of the Lib Dem "surge", and the surprising reduction in the party's representation in the House of Commons, Mr Clegg held the future of British politics in his hands as we went to press. If, as many in the Westminster village suspect, he opts for a deal with the Conservatives, progressives inside and outside his own party, will surely never forgive him. He will have squandered an unprecedented chance to break the political mould.

Whatever happens, Mr Brown's political career is at an end. He has been one of the commanding figures of post-war British politics; his legacy will be the way he increased public spending, transformed the NHS during the years of the long boom and his response to the near-complete collapse of the banks. He acted decisively to prevent recession from becoming depression. His example was followed throughout the western world.

Now, in one of his final acts as Prime Minister, Mr Brown has sought to open the way for a possible progressive coalition that could and should have been created during the past 13 years. Too late, perhaps, too late . . .