It's a safe bet that the advance publicity will not blunt the report's impact when it comes out on Thursday. But we are impatient for more than the relatively stale news that it recommends a Parliament made up of a mixture of constituency MPs and others to top up the final outcome, to make it more in line than the present system does with the proportions of the national vote each party gets; that he and his committee propose a narrow range of percentages of which 83 per cent of constituency seats to 17 per cent top-up is the mean; that his system would have delivered a single party overall majority in three out of the last four elections - though 1979 would have been a close shave - and that the constituency MPs will be selected by a system which allows voters a second as well as a first preference.
But what about the less technical questions? What, above all, will the Prime Minister say about it? And - a different question - what will he do about it?
Mr Blair could reject or embrace the report outright. Or he could, and almost certainly will, adopt a (wait for it!) third way: not only welcoming, but also complimenting the report, commending it to the British people for national debate, making it clear that neither Cabinet nor party has taken a decision, and setting no date for a referendum. But he may give the impression also that he is coming round to think there just might - other things being equal - be something in this electoral reform lark after all. He will not commit himself - but he will be significantly warmer toward Lord Jenkins's recommendations than the outright opponents of reform in his own party would like him to be.
This will still be a disappointment to the zealots among the supporters of electoral reform - and there are many of those increasingly restive elements of Paddy Ashdown's party. Indeed their disappointment will be all the keener after yesterday's titillating (to them) declaration to Sir David Frost by Robin Cook, the Cabinet's most senior champion of electoral reform - and therefore rightly licensed to speak his mind - that he has "no reason to believe" that the Government will not honour its promise to hold a referendum on electoral reform in this parliament.
Unless the Prime Minister repeats Mr Cook's language on Thursday - and there is no sign that he will - it follows that he could still be thinking of postponing a referendum until the next parliament. And that will worry the zealots a lot.
First, the hopes of change rest on the widespread - but still highly hubristic - assumption that the Tories will lose the next election.
Second, if a squeaky-clean Prime Minister committed to bringing back honest politics is prepared even to contemplate paying the price for breaking a manifesto promise on this issue, can he really be that serious about the idea of reform in the first place?
The zealots should pause and think before they complain, for several reasons. The first,and most obvious, is the stunning apathy on the issue among the electorate at large. It will take time even for the Jenkins Report to arouse sufficient excitement to guarantee even a minimal turnout in a referendum. One of the under-appreciated lessons of the referendum on Welsh devolution was that there were great difficulties in persuading voters to support something to which they were not as much violently opposed, as indifferent.The other is that not even the imprimatur of that nice, hugely popular Tony Blair is enough to guarantee a comfortable majority.
Moreover, Lord Jenkins's report argues firmly that a change in the system is not practicable, because of the detailed boundary changes it will entail before the next election.
This has allowed Mr Straw, the Home Secretary, and other sceptics to argue that it is illogical to have a referendum on changing the system, followed by an election under the system that the electorate may just have voted to end. But it also brings into sharp relief the point that whether or not the referendum takes place in this parliament is irrelevant to when, if at all, the system is changed.
Another little-noticed point is that Lord Jenkins backs Lord Neill's proposal for an electoral commission; the complex and difficult decisions on Neill, including his controversial provisions for referendums, will surely have to be taken before a referendum on Proportional Representation can go ahead.
This will not satisfy some of those Liberal Democrats posturing menacingly around Mr Ashdown, which is one reason why Mr Blair will not rule out the possibility of a referendum in this parliament. Nor is one absolutely impossible, either late in this parliament, or even, just conceivably - if opposition in the Labour party could be squared - on election day itself.
Which brings us to the other reason for pessimism among the reformers: opposition to electoral reform within the governing party itself. In one important respect, Lord Jenkins is helpful here; by prescribing that top-up candidates should be grouped in ones and twos, tied to subregions of cities and counties, and by declaring his committee's strong objection - endorsed at every public meeting he held during his deliberations - to closed party lists, he offers at least the opportunity to meet one of the objections held by some on the left : that a new system could be used as an instrument of centralised power.
But Labour resistance also stems from something else - from tribalist exaltation at the 1 May 1997 election result under the first-past-the- post system. This is a party still high on its landslide; the local and the European elections could change the party's psychology sharply. A Labour party that can at last grasp the possibility that it is politically vulnerable may start to look more favourably at electoral reform.
For Mr Blair this is an issue of extreme delicacy, the first big one on which the modernising tendency in the Labour party is itself split. A majority in the Cabinet are resistant to reform. John Prescott, among others, is a formidable opponent of change. A referendum in this parliament remains less likely than one in the next.
But Mr Ashdown, who will (with backing of his parliamentary colleagues) soberly but firmly endorse the Jenkins report this week, will remain in play for the time being. Nobody can know for certain what the final outcome will be.
The prospect of electoral reform remains at the end of a long fuse. The fuse could burn out any time between now and the detonator needed for the seismic change in the electoral system envisaged by Lord Jenkins.
All you can say is that it will be burning just a little more brightly after Thursday.Reuse content