Steve Richards: Almost everything you think you know about the PM is untrue

Forget about the evasively familiar battles over debt and plans for growth. Piers Morgan's interview with Gordon Brown was the most important event in the pre-election campaign so far, with its tears, laughter and selectively frantic dash through a troubled life.

Whether we like it or not, this election will be determined by personality. Unusually, three party leaders fight a campaign for the first time. None of them have sought to be Prime Minister before in an election. This has not happened since 1979, all of them untested as election leaders.

I am also struck by how quickly conversations with the parties' leading figures move to personalities, more so than in recent campaigns. Labour's opponents tell me their internal polling takes their breath away. Brown is not merely disliked. He is loathed. Not surprisingly, therefore, the Conservatives in particular would like to make this campaign about Brown, or their chosen stereotype of Brown. They hope to win partly on an "anyone but Brown" basis. In the meantime, they play what they regard as the Cameron card. I cannot recall large posters of an airbrushed Michael Howard or William Hague launching previous pre-election campaigns, unless their images were on Labour's posters. At the turn of the year, Cameron was here, there and everywhere. He had chosen to become an issue.

Labour's strategists focus on him, too. They discover that voters do not trust Cameron, the image of the bike with his car behind him being the one that resonates most. They add hopefully that voters are warier of George Osborne, the apparently privileged smirk and the boyish demeanour at odds with the gravity of the crisis. In Downing Street they also know that such perceptions do not get them very far if voters are determined to remove the weirdo in No 10 who throws plates around and only cares about clinging to power. If they can change that perception then the focus moves more intensely on to the duo on the other side, the untested characters who stroll without too much scrutiny towards power. That is why Brown ended up on a programme he was highly nervous about doing and why the stakes were so high. Brown has only a few weeks to become a more human public figure and not a one-dimensional speak-your-weight machine going through a tough time. The performance was never going to be a game changer, but he needed to clear some ground in order to make any headway at all.

A common view on the blogs and in the newspapers was that the exercise was pointless because voters have already made up their minds on Brown and will not change them now. I disagree. Voters have made up their minds about Brown more than once. Indeed, they change on a frequent basis that must be exhausting for them and for him. Here is a compressed history of his fraught career, the wild oscillations in the way he is perceived both by voters and in the media. Take a deep breath, as it is quite a ride.

In 1992 Brown was so popular and respected he was the automatic choice to become Shadow Chancellor, an appointment hailed by the newspapers as a sign that Labour might become a serious force again; in 1994 he was so unpopular he did not dare stand against Tony Blair for the leadership; by 1997 he was so authoritatively popular that newspapers hailed him as the Chief Executive of the Government and the obvious successor to Blair; in 2001, after September 11th, he became a marginal figure as Blair bestrode the globe, with many columnists arguing his day had passed; after his radical 2003 Budget he was widely hailed in the opinion polls as the star of the Government and in the newspapers as a Lloyd George-style radical; by 2004 he was so unpopular that Blair felt able to marginalise him from the election campaign; in 2005 he was so popular Blair brought him back to run the election; after the election he was so disliked that polls suggested that he would be a more unpopular Prime Minister than Blair; when he became Prime Minister he became so popular that he was tempted to call an early election; after he did not call the election he became the least popular Prime Minister in British history.

Although unlikely at this late stage, there is a small possibility that perceptions will change again. There is no one else at the top of politics who has had such a bumpy ride. To take the most recent examples, Blair was loved to the point of idolatry and then loathed with an intensity that bordered on a form of madness. John Major was briefly admired and subsequently viewed with disdain. The distinct oscillations in Brown's case are explained by the deliberately evasive public figure, a largely blank canvas with mysterious splashes of paint here and there. Easily voters can respect him when things are going well and turn against him when the opposite is the case. Things have been going badly since he became Prime Minister to such an extent that I should add in my account of his ups and downs that the down has been pretty constant after the early autumn of 2007.

So what of the programme: will it help to clear the ground, to let him make one more attempt at an upward bounce? The production values did not help the viewer, the impatient editing that did not allow the interview to breathe for more than 10 seconds before we were off again to some other theme or subject that made those watching feel like they had entered a bad 1970s disco, the noise and cheap flashing lights. Interviewees are more interesting when they are seen in conversation rather than edited into a sequence of stilted sound bites. As shown, Brown was not exactly the free-flowing deft conversationalist to challenge the caricature. He was rarely captured uttering more than a sentence.

But the sequence as a whole did convey a more rounded and real figure. It countered the stereotype. The more compelling themes were not the one that seized the attention, the death of the daughter. More striking were the early days as Brown sought to raise money for Africa and at Edinburgh University when he became the glamorous student rector. For voters seeking conviction and depth, the photos of the long-haired campaigner were a flattering contrast to those of Cameron and Osborne at the Bullingdon Club.

The end of the interview was also revealing. Brown was asked what he would do if he lost the election. He claimed he would run a charity. Perhaps the answer was rehearsed for wide approval, but I doubt it. His only public answer, even in an attempt at humanisation, is to insist that victory is all he is thinking about. I have never heard him contemplate the consequences of defeat in any circumstances. Rehearsed or not, the answer seemed truthful. There are fruitful personality dividing lines for Brown in some of this.

The Sun's attack last autumn on Brown for misspelling a grieving relative's name produced a rare outburst of sympathy. I suspect the mood change is heightened by the interview. Brown's awkward authenticity might not be a vote-winner, but perhaps he will not be such an easy card for the airbrushed Conservative leadership either. Suddenly the contest over personalities becomes more interesting and a little less predictable.

He made the right decision to appear with Piers Morgan.

s.richards@independent.co.uk