Steve Richards: Brown's political hell is all but over; for his rivals the nightmare's about to begin

By next week we could be back to the early 1990s with a right-wing dominated party screaming about Europe, demanding even bigger spending cuts

Remarkably the campaign ends with voters more engaged than they were at the beginning. Almost certainly turnout will be higher than last time. The outcome appears to be close. There have been plenty of twists. No party has soared in any other campaign as the Liberal Democrats did after the first televised debate, even if their support has since declined.

Change is the most potent word in politics, conveying a conveniently imprecise sense of fresh energy. Much change is promised, and one way or another voters will get it tomorrow. Look at the fate of the three leaders who have dominated this presidential campaign. Whatever happens their political lives will never be the same after today.

Barring an astonishing turnaround Gordon Brown is spending his last day as a Prime Minister leading a government with a safe overall majority. Quite possibly his extraordinary political career is about to end, although I would never write off entirely a figure who has been written off so many times before.

Brown has come to semi-life this week, delivering a series of speeches with passion and a hint of wit, an echo of his performances in the 1980s. Like Neil Kinnock when he was Labour's leader, Brown had consciously purged his public image of any life in order to appear "prime ministerial" and respectable.

In both cases the metamorphosis was a misjudgement and a weird one, opting to lose personality for the sake of appearing like a bank manager on a bad day. Since 1992 Brown has been at the top of politics. The intense heat, some of it self-generated, has taken its inevitable toll. He is exhausted. Perhaps the sudden eruption of oratory is almost a sign of relief that whatever happens today an end of sorts is in sight. A phase is over, one that has been a form of political hell.

David Cameron must feel even stranger. Tomorrow he could be Prime Minister, a spectacular achievement by anyone's standards. Yet in spite of Labour's unpopularity, an economic crisis and substantial media support it is possible that he might not make it to No 10. Even if he is the occupant he will not win a big majority. His Blair-like approach has not produced a Blair-like result. The proclamation that his party had changed was never matched by a new policy agenda that proved it had done so.

Instead, by next week we could be back to the early 1990s with a new right-wing dominated parliamentary party screaming about Europe and demanding even bigger spending cuts than those already being contemplated in George Osborne's "emergency budget".

If Cameron fails to form even a minority administration he could face a leadership challenge; more probably he will have to genuinely change his party. After his nocturnal campaigning Cameron must feel tired, but his career is about to become incomparably more energy-draining. The same applies to Nick Clegg too. The most joyfully uncomplicated phase of Clegg's career ends today.

He has flourished in the campaign and gets a hero's welcome wherever he goes. Tomorrow will be different. If the Conservatives win an overall majority and Labour are second, in terms of votes as well as seats, he will become a leader who almost broke the mould – like his SDP/Liberal predecessors in the 1980s.

He will face the daunting challenge of raised expectations but without any fresh instruments to meet them. At the next election he will no longer be new. But if there is a hung parliament Clegg might have a nightmarish decision to make, and then have to persuade the rest of his party to accept it (not necessarily a straightforward task). If he works with Labour he will get a referendum on electoral reform.

But he has already said he will not prop up a defeated Brown. If he allows Cameron to form a minority government his chance of a new voting system will pass. No wonder he has joked he would prefer to keep campaigning.

Everything changes for the leaders tomorrow, and for us too. Do we want the space for new forms of progressive politics or a Conservative administration? Today we have the power to determine the nature of the change. Tomorrow it will be too late.