Steve Richards: Unless Brown breaks free from the shackles of his past, he will never engage with voters

Every public word was carefully rehearsed, every phrase analysed intensively before delivery

Sooner or later political leaders are trapped by their own pasts. Gordon Brown is caught in a stylistic trap, a manacled constraint that served him well long ago but threatens to be a fatal incarceration now.

On the BBC's Today programme yesterday Brown was asked whether he enjoyed being Prime Minister. He could not answer this simplest of questions. Instead he spoke awkwardly of the daily challenges in the job and the dutiful inspiration of his father, obtuse responses and ones that are so familiar they are already tediously formulaic.

The Prime Minister was equally over-rehearsed when reflecting on the tough decisions he would take in relation to what he repeated too many times were the long-term challenges. A listener could almost hear the agonised calculations: "I must not say I am enjoying the job as that would sound frivolous ... I must get across the idea that I am meeting the long-term challenges and imply that Cameron is incapable of doing so."

Why can't Brown answer questions in an engaging way? It is one of the easiest of the political arts and yet he treats some interviews as if they were the equivalent of swimming the Channel after a 26-mile run, nightmarishly arduous and demanding a range of contortions.

The answer relates entirely to Brown's past. He dispensed ruthlessly with some of the communicators' arts in 1992, the year he became shadow Chancellor after Labour's fourth successive election defeat. Before then he was almost as compelling in the public arena as he still can be in private. Along with Tony Blair, Brown was the figure that Peter Mandelson wanted on every broadcasting outlet to prove that Labour had changed. In the Commons he was a brilliant debater, funny, forensic and utterly self-confident.

But when he became shadow Chancellor he tied himself in chains. Brown had to turn around Labour's deeply embedded reputation for economic incompetence, knowing that one word out of place could lead to yet another catastrophic election defeat. From 1992 he lived in fear that a clumsy phrase about tax, a spontaneous reflection on the need for more public spending, a hint of frivolity with such a serious task ahead and the fragile edifice would collapse. As a result every public word was carefully rehearsed. Every phrase was analysed intensively before delivery in case there was somewhere within it a touch of recklessness.

The same diligence applied from 1997 when Labour was under even more intense scrutiny in government. Could it really deliver economic stability? Would Labour go on a tax and spend spree once in power? Again one word out of place about, say, the tax burden, or the purpose behind the prudence and there was a danger that conservative middle England would turn away from its tentative flirtation with Labour. In spite of being the most avid reader and lover of language to have occupied Downing Street for decades Brown clung to the safety of a few utilitarian phrases.

Brown's linguistic caution, his lack of spontaneity, the speak-your-weight answers were not only unavoidable then, they were acts of astonishing self-discipline. His enemies, including some within his party, underestimate still the achievement of turning around seemingly permanent perceptions about Labour in relation to the economy.

But now the chains imprison him, extending their reach even beyond interviewing techniques (although listening to an interview is the closest most voters will get to a political leader and so are supremely significant). The chains have constrained his broader New Year narrative too. In interviews Brown speaks of the tough decisions, as in the 1990s he highlighted the "tough choices". In some of his interviews he explicitly refers to his period as shadow Chancellor when he took a robust line on public spending commitments as he is doing now over public sector pay. The emphasis is on solidity, competence and experience as it was when he was prudent for a purpose a decade ago.

As a public narrative it will not be enough. We know it will not be enough because in essence that is the card Brown played throughout the latter part of last year. His final Downing Street press conference in December highlighted precisely the same themes. In interviews during the late autumn, amidst the storms that erupted around him, he also stressed he was preparing for the longer term as well as responding to unexpected events. At least no one can accuse him of performing a John Major-like "relaunch" as in Brown's case the songs remain the same. When he sung them in the autumn Labour's poll ratings slumped.

Brown is not in an easy position. If he had returned from his brief Christmas break and preached a series of different messages he would have appeared in a wholly inauthentic light. But voters want more than staccato rhythms of the 1990s.

On one level Brown recognises this. He says, again too repetitively, that the challenges now are different from 1997. He also was speaking genuinely when he told Today yesterday he wanted to engage in all the debates. More than any other British politician he is gripped by ideas and arguments, reading and engaging with an extraordinary range of writers, economists and thinkers.

But he needs to paint in bolder strokes. In his early years as leader David Cameron sensed a new political mood when he placed a distinctive emphasis on well-being and happiness. We wait to see whether Cameron has any policies to meet such ambitious themes. But there is a language around quality of life that is missing in Brown's big tent narrative of competent reliability.

Can Brown break free of the chains he voluntarily acquired in 1992 and which helped him and his party to acquire power? Ominously for him, other prime ministers have struggled to escape their pasts. Shortly before he died Jim Callaghan admitted to me that he had failed to read accurately what was happening in the late 1970s.

He had been brought up politically in the recession of the 1930s, conditioned to fear unemployment more than any other issue. After losing the 1979 election he realised that the conditioning of the 1930s was not appropriate for the problems of the 1970s. His past had guided him treacherously to make the wrong moves.

In the summer of 1974 Margaret Thatcher became a star of the Conservative Party by pledging to abolish the rates when she was their shadow environment spokeswoman. Remembering her soaring success then she could not see the dangers when she finally carried out the pledge and replaced the rates with the poll tax in the late 1980s. She too was trapped by her past.

Brown is incarcerated only in a presentational trap. It should be easier to escape, but he shows no signs of doing so yet and time is running out.

s.richards@independent.co.uk