The Conversation is bigger and more clever than it sounds. But is it enough?

How can a Prime Minister supposedly bursting with convictions and without a reverse gear lead a Big Conversation with the country? The whole premise is easy to mock. "Hello... is that Burt Thung in Dewsbury? It's Tony Blair on the phone. Have you any ideas for the next manifesto?"

Yet in limited, less trumpeted forms Tony Blair has held such conversations before, while proclaiming a determination to lead from the front. Indeed New Labour has turned the parading of inconsistent slogans into an art. In the build-up to the 1997 election Mr Blair promised to transform Britain into a "young country". It was nothing less than a call to revolution. At the same time the somewhat less inspiring slogan "We Can Make A Difference" was being bandied about. In the early years of his leadership controversial policies were subjected to widespread debate. He announced that referendums would precede the introduction of a Scottish Parliament and a Welsh Assembly. There is no louder conversation than a referendum campaign.

Before the minimum wage was introduced Mr Blair and Gordon Brown were careful to put the case in stages, arguing about the principle for years before announcing the details. The policy was implemented smoothly and with the support of some who had originally opposed it. A similar pattern was apparent in the decision to increase National Insurance contributions. A consensus was reached about the need for NHS extra funding, and other sources were convincingly ruled out. At the end of a carefully managed sequence of events Gordon Brown announced a substantial tax rise that proved to be highly popular. If the increases had been out of the blue I suspect all hell would have broken loose.

One of the reasons why all hell has broken loose over university top-up fees was the conspicuous lack of a conversation in advance, let alone a big conversation. Last year a series of announcements were made haphazardly and without much strategic thought. At one stage we heard that the Government wanted 50 per cent of school leavers to go into higher education. Meanwhile university vice-chancellors warned that they were already seriously underfunded. Unconnected from this cry for help, Gordon Brown set up an internal inquiry into whether universities could be doing more to raise cash from the private sector. Then under last autumn's provocative but vacuous banner of "boldness" the Government announced, as if from nowhere, its plans for top-up fees.

It is not easy to predict how many Labour MPs will rebel. More than 100 of them have signed an early day motion raising questions about top-up fees, but the wording is woolly. At no point does it declare explicit opposition. The motion was worded to maximise the signatures rather than to dissect the Government's proposal. This is not a great surprise as none of the opponents of the policy have come up with a credible or fairer alternative. As far as I can tell they do not have one. The Government has dared to come up with a policy that will lead to an expansion in higher education without parents having to pay more. Students will not have to repay interest-free loans until they are earning decent salaries. At the same time universities - most of which are complacently inefficient - will have to sharpen their performance as they compete for students who will want to be getting their money's worth. If a Big Conversation had preceded the details the Government would not be facing the possibility of a calamitous defeat.

Although I know of nobody who would hail a "small conversation", the Government's big version is therefore more important than it seems. We should not get carried away. The exercise is more about presenting voters with the challenges facing the Government, and nudging them towards the controversial policies Tony Blair would like to adopt. It is not that he has no idea what he would like to do. He seeks wider support before he attempts to do it. Margaret Thatcher would not have approached reform in this way, but Mr Blair has more of an excuse. In trying to revive the public services he faces more daunting hurdles than those Mrs Thatcher leapt over with relative ease in the 1980s. The privatisation of several state-owned industries was radical, but relatively straightforward. Similarly it was much easier to virtually kill off local government in the 1980s than it is to revive near moribund councils now. With most of Mrs Thatcher's reforms there were immediate gains, at least for some. The acute problems came later. In contrast, this Government is reversing decades of underfunding in public services and seeking to address some of the complacent conservatism that accompanied the decline. Often this means short-term pain to bring about some longer-term gains: tax increases, giving power to councils that have had no recent experience in exercising it, charging to drive on roads.

The document that accompanied the launch of the "Conversation" poses genuinely difficult questions. Implicit in some of them is the daunting conundrum that has been at the heart of recent Blair/Brown tensions: how to devolve power in public services when the Government is responsible for raising taxes to pay for them? Other questions raise equally thorny issues, suggesting that the Government is moving towards support for compulsory pensions, more congestion charging and motorway tolls. Here is an example of how a mature political debate could work. The director general of the CBI, Digby Jones, rightly complains at the appalling state of transport in Britain. He moans also about the tax burden. So, if he does not want to pay more tax, how to deal with the transport crisis? Before long a consensus might emerge in favour of far more extensive charging. Tony Blair would have no choice but to be bold on behalf of a public screaming to pay for better transport.

Whether the "conversation" will proceed in quite such a convivial way is another matter. The Government is trying to renew itself at a time when the goodwill of the early years has evaporated and when Mr Blair faces a credible Tory leader for the first time. Although the Tories lack credible policies, I predict that they will be 10 points ahead by the spring. The Conversation should have happened early in the rosy first term when ministers tended to avoid "hard choices" while claiming a prime ministerial visit to a council estate was a welfare revolution. Now Hutton hovers, Iraq implodes and Michael Howard is getting an easy ride. The easily mocked Big Conversation is a project that deserves to succeed, but many other noisy voices will get in its way.