On Friday the curtain came down at last on the most addictive show in British political theatre. After a very long run, the Labour Party conference voted last Monday to transform itself. The new show will be more dependable and less exciting. It is impossible not to be nostalgic for the greatest conference performances of the past: Ernie Bevin at Brighton in 1935 excoriating George Lansbury for "hawking your conscience round from body to body" ; Aneurin Bevan refusing in Brighton in 1957 to go "naked into the conference chamber" without the atomic bomb; Hugh Gaitskell promising in Scarborough in 1960 "to fight, fight, and fight again" for the party he loved: John Prescott's "head on the block" appeal for one member, one vote at Brighton in 1993. But sentimentality is out of place.

Delegates and journalists may have delighted in fratricide-by-the sea, but the voters did not. The behaviour of the party conference when Labour was in power helps to explain why it has been so much less successful a party than the Conservatives. Labour has never won consecutive full terms in power. One reason why is that the activist hegemony never represented the silent majority of Labour supporters in the country, let alone the wider electorate, and the most heroic speeches from past conferences were attempts by the leadership to get the conference to give the wishes of the electorate priority over ideological purity. The Labour left has a proper place in politics, but its job is to win the argument in the country as a whole, rather than to manipulate the endorsement of the unions which still command an influential conference vote, or the constituency parties where members prefer not to attend time-consuming meetings. Besides, the new conference style will not guarantee an easy passage for all the leadership's policies. If the National Policy Forum fails to reach consensus for the final version of its "rolling programme" of policy making, union and constituency opponents will still have the chance to press for changes - although it will come only once in each parliament. Once every five years, rather than once a year, does seem unnecessarily paltry.

Despite this, the Prime Minister deserves congratulation for continuing the process of reconnecting the party to the aspirations of the broad mass of Labour members and supporters. Not that this means he he can eliminate dissent. Over the next 18 months, there will be plenty of it. Mr Blair deserved to carry all before him in Brighton, but the hard choices he spoke of will almost certainly be harder than some of his ministers realise, never mind many of the 93 per cent who are satisfied with his performance. Some of the hard choices will impose strains on unity in the party and the cabinet.

Sticking to the previous government's spending totals will cause problems, and they have not begun to rebound on the Blair administration. They may not do so for many weeks, but the public will become used to the fact that not every problem can be blamed on the Tories. When consultants start campaigning for emergency funding for the NHS this winter, when patients denied hospital treatment die, it will be Frank Dobson and not Stephen Dorrell who will take the blame for saying no. The government will make itself unpopular with teachers for holding the line on public sector pay, despite its insistence that education is its highest priority. Since union leaders have done nothing to cool anticipation among the low paid, the government will be attacked for fixing a minimum wage that is well below their expectations. Welfare reform is certain to make enemies for there will be losers as well as gainers, as there were from the imposition of student tuition fees. The list will lengthen.

The Prime Minister's speech demonstrated a belief that his New Britain will accept change even if it does inflict pain - that welfare reform will happen if voters can be persuaded that there is an idealistic motive behind it. But it does mean suffering pain before realising gain. Mr Blair has a vision of the modernised, socially cohesive, universally educated country, he wants to see before the end of the parliament in 2002. Because they are so intent on a second term, the Prime Minister and the Chancellor of the Exchequer are determined to avoid the errors of previous Labour governments, which listened to the siren voices of the conference and grew accustomed to postponing unpopular decisions. Last week was the end of the beginning. It has been a good beginning, but now the going gets tough.