This week's brief eruption in the submerged struggle between Gordon Brown and Robin Cook over Labour's attitude to the single currency reminds us, or should do, that we don't really know where Blair stands on the two great issues which will define his position in late-Nineties politics.
The issues are the single currency itself, and political reform generally. They are not, in that strangely archaic expression, bread-and-butter questions. But how Blair plays them if he wins office will define the sort of country we live in around the year 2000.
A fifth consecutive Tory victory would produce clear answers: it is inconceivable that they would vote for the abolition of sterling or embark on root and branch reform of the system that has yielded them such rich rewards.
But Blair could still go either way. He could decide against EMU for the time being. This would remove the Tories' biggest unifying issue in Opposition - it would cancel heroic parliamentary scenes currently being dreamt about by Portillo and Redwood. It would also ensure that Labour didn't need an austerity programme to prepare for membership; instead, the new government could enjoy the fruits of the economic recovery.
Caution on EMU would sit naturally with caution on the constitution. Blair could limit himself to reluctantly implementing a minimalist Scottish assembly and turning the Lords into an appointed super-quango. New Labour would inherit the earth, and not seek to change it very much.
Compare that with the alternative, in which Labour Britain embraces its federal European future and goes quickly for radical reform at home. Membership of the single currency is matched by the passing of powers to English cities and regions as well as to Scotland and Wales. And partly because of the difficulties of getting this through Westminster, Blair unleashes the pro-European centrist consensus so long hidden in British politics, by announcing his conversion to voting reform.
This is not impossible. Serious Tory tacticians are seriously worried about it. If the talks on constitutional reform between Labour's Robin Cook and Bob Maclennan of the Liberal Democrats, publicly announced yesterday, are not merely cynical, they suggest that Labour is alive to the possibility of a referendum leading to a different electoral system.
That, in my view, would mean the Lib Dems moving away from some of their purist positions on PR; whether they are able to or not may yet become the litmus test of their seriousness as a national force. Such a Lib-Lab deal is full of dangers but also of opportunities. By making it rational to back smaller parties, voting reform might split the old Conservative party into rival Christian Democrat and British-Nationalist parties.
If that happened, Blair would find himself presiding as ring-master over a majoritarian alliance of new Labour, Liberal Democrat and even pro-European Conservatives. By conventional calculations, such a parliamentary leader would be almost impossible to dislodge, having achieved the kind of remaking of a previous political order that even the ineffable Bill Clinton can only dream of.
Heady stuff, isn't it? Certainly, these are disconcertingly different new Labour futures. One is the continuation of the present by other means, the other a radical break.
Choosing between them will affect almost everything in public life. Staying outside the Union and avoiding deep reforms would buttress today's mild English conservatism. It would confirm Britain as a country in which croney- politics worked - the small village-nation Rupert Murdoch exploits so well, a land of private clubs and handshakes dominated by a few friendly players. Going the other way would release energies, shake up the old hierarchies, change the shape of power. Potentially, it would make Tony Blair a reformer of the historic stature of Gladstone or Lloyd George.
Yes, in the real world, the choice would probably be more muddled and ragged-edged than it seems when briefly sketched out by a journalist. But, given the great forces at work in European politics and the senility of the British political system, Blair couldn't eventually avoid such a choice. The underground battle between Gordon Brown and Robin Cook is part of this argument. Cook is more of a political reformer than Brown; yet he is also more sceptical on the currency question.
In all this, Blair seems to be standing back and observing the argument without finally committing himself. His colleagues endlessly discuss what his own deep views might be. They assume that Blair is slightly more hostile to EMU than Brown is, and that he is also more hostile to voting reform than Cook is. But they're guessing.
The Blair-Brown-Cook conversation about all this is intense, and private and has not leaked - which says a lot about new Labour's pre-election self discipline. Keeping it quiet is very clever politics, since Labour's potential voters are divided between those who hope Blair's a radical and those who are scared stiff that he might be. But as the election draws nearer, the country needs to know more. It is time to start tapping on the glass.Reuse content