The third argument for Labour's cautiousness is only slightly more convincing. It starts with the observation that Mr Major is struggling desperately to gain stature and authority. He will be severely tested as the economy goes further into recession, and the community charge still thumps onto people's doormats. The recession will limit his capacity to spend more on health and education and fatally undermine his claim to be concerned about these issues. In this scenario Labour needs to play safe, while the Tories' waning popularity in the country takes its toll on Mr Major's position.
There is something in this approach. The economy could easily be in a mess by the time of the next election. But it leaves far too much to chance. Mr Major has swiftly moved towards the middle ground of politics. Unless Labour develops its policies the next election will be a battle between two parties with virtually identical economic policies. The choice will be between two Euro-pragmatist, technocrat, cautious, managerialist parties. In such a contest everything will hinge on the state of the economy and whether Mr Major and his team are trusted more than Neil Kinnock and his.
But the main reason why defensiveness is not enough is that it has never been enough. Labour's policy review made Labour an effective anti-Thatcherite force. It now has to become a modern social democratic party which can win because of the popularity of its vision. Rather than respond defensively, Labour should see this as an opportunity to break out of the straitjacket politics of the Thatcher era.
One step which Labour could take is to adopt the final part of the SDP/SLD agenda which it has not yet embraced - electoral and constitutional reform. This would open a distinctive new front.
A second theme is the reform of the public sector: how it is financed, structured and managed, from education and health through to local government, will be the major issue of the 1990s. Labour needs to match its commitment to spending with innovative ideas about service delivery, financing and management.
Under Mr Kinnock's leadership Labour has shown considerable capacity for discipline. That allowed it to weather the Thatcher bombardment. Now it is time to come out of the bunker and display some other qualities, chiefly some political creativity.
(Charles Leadbeater is industrial editor of the Financial Times.)