Is New Labour all spin and no policy? It's time for Blair to get aggressive to regain the initiative
There Is a line in Jane Austen's Persuasion which captures Conservative Central Office's view of Tony Blair: "It is the worst evil of too yielding and indecisive characters, that no influence over it can be depended on." In other words, New Labour may appear prudent and worthy of the electorate's trust, but the speed of its reform is the precise reason that it is neither.

This view is delivered with a kind of mischievous fatalism by the Tories. They know that they lag too far behind in the polls to succeed on 1 May, but in the meantime they are at least going to have some fun with Labour's leader and its manifesto. This approach has brought unexpected success in the running battles between the Labour Party headquarters at Millbank Tower and the Tories at Smith Square.

Labour's pristine coherence was damaged, firstly with the party's evident confusion over the privatisation of air traffic control systems, then with Gordon Brown's expenditure plans, and finally on the question of exactly which privatised utilities would be subject to the windfall tax. Conservative arguments were appealingly simple, particularly where they pointed out that the one-off windfall tax would not raise enough to finance a running programme of youth employment.

One suspects that the electors find these issues pretty resistible, and that we have not yet reached the point where the large number of waverers latch on to the themes that will push them one way or the other. Still, the Conservative tactics this week have been interesting, and on current form they will go on scoring. They have discovered judo politics - that is to say, they are using the weight and energy of the assailant as their main weapon, turning Labour's words against itself. "It's very simple," explained a Tory strategist. "Over the last two years people have tended to believe what Labour say rather than us. Now we can say, if you do believe them, would they please make sense of the following statement by a Labour spokesman three months ago. The questioner is sent away with a Labour assurance which then turns out to be false, or incomplete. When the questioner returns with more information they have no position to fall back on whatsoever."

This was more or less the order of events over the privatisation of air traffic control. The Tory- inspired question was met with Labour spin. Then the secondary question was met by fudge and a rather too testy statement by Mr Blair, who insisted that privatisation was a Tory idea in the first place. Indeed it was, which begged the question; why on earth were they being caught out on it when there is a Conservative record of five years to address?

The beauty of this strategy is that the Government has not yet seriously had to defend that record, or even its manifesto. It has also allowed John Major to go through his election high-altitude training and appear on the race track giving a passable impression of confidence. By contrast the Labour front line - Cook, Beckett, Brown and, occasionally, Ann Taylor - have a wan appearance at the morning conferences which suggests they are all terrified of being found out.

Even Tony Blair patrols the room with a nervous swing of his eyes, as if he were about to be subject to some terrible form of exposure. In the light of the polls their behaviour seems baffling, but it may have something to do with the rigidity of the manifesto text, from which they may not depart without serious risk. They cannot go off-piste to extemporise and dazzle us with their vision and sense of mission. Instead they stick to the narrow manifesto proposals and wait for the Tory flak.

The Tory spin on this is that Labour is relying too much on spin. "They are brilliant at the presentational, immediate strategy," said the tactician. "But they do not put an equivalent intellectual effort into their policies. We have been surprised when asking them questions - for instance, about what they are going to do with the trade unions and employment law - how they don't seem to have worked out an answer."

After a rather pallid week, Labour is insisting that it has not yet put a foot seriously wrong. Trust, they say, still remains the big issue, and there have been other notable victories. "On devolution," said a Millbank spin doctor, "we made it clear that there weren't going to be any tax rises and that sovereignty was staying at Westminster. That's two-nil to us. On the single currency we got across the message that we were unlikely to join. On the unions, it's clear that we are not going to back to the Seventies. And on business and the private sector, we got the message out that we have changed and we are not committed to dogmatic public ownership any more. "

This is the programme of reassurance that New Labour began to devise two and half years ago. It is working well for them, at least on one level, but it is also a necessarily defensive strategy which presents the Tories with opportunities. And perhaps it relies too heavily on the sweeping action of Peter Mandelson's team, rather than on intellectual back-up which can be deployed as the argument moves through the day. The fact of the matter is that wars are not simply won by aggressive propaganda. It helps, but it has to be matched by an aggressive strategy. The inherent nature of the Labour platform is still surprisingly passive.

Over the coming weeks Labour is bound to try to change this. There have been suggestions in the corridors at Millbank that Gordon Brown's overall responsibility for the campaign may be snatched away by Tony Blair. The Tories are encouraging this idea, if only because it helps them to paint the opposition leader as a control freak at odds with the spirit of his party, who cannot let it speak for itself. They also enjoy the idea of the vaunted Labour spin machine falling apart. But of course it isn't; the truth appears to be that Mr Brown does not want to chair every morning press conference and would willingly hand over to Donald Dewar. But Mr Dewar is needed to fight the campaign in Scotland. Anyway, this is a mere detail - the crucial process of persuasion started so long ago that it cannot be undone by the daily skirmishes.

In the immediate future the Labour Party is expected to launch its offensives on education and health, while keeping up the pressure on the key question of trust. The Prime Minister will reply by focusing on the idea of Labour's congenital lack of the same commodity when it comes to managing the economy. There will be much obfuscating spin, which is why, while listening to it all, we should perhaps recall another observation from Persuasion, which exactly describes the process of persuasion conducted through the media: "Facts or opinions which are to pass through the hands of so many, to be misconceived by folly in one, and ignorance in another, can hardly have much truth left."