In practice, based on certain assumptions about the 1992 election, that means the Liberals would win 2.6 parliamentary seats for every percentage point of the nation's votes they gained, while Labour would win six seats. The result is a system barely more proportional than the existing one, and which would neatly boost Labour's chances while doing little to redress the underrepresentation of the third party that is the most glaring unfairness of today's procedure.
This, then, is the result of months of work by Professor Plant and his colleagues. Mr Smith, however, has not even endorsed the findings. After declining so far to say what he believes himself, Mr Smith yesterday said that he saw no case for change but was willing to put the matter to a referendum so that the electors could decide it. If the Labour Party conference backs his view, he will at a stroke have postponed discussion of this contentious issue until after the next election.
So much for first impressions. On closer inspection, however, the Labour leader appears to have done a fair day's work. Since his primary aim was to avoid splitting the party, it would have been hard for him to come out wholeheartedly in favour of reform. What he has done is only slightly less valuable. He has broken, for the first time, the united front against PR maintained by the political establishment of government and opposition. When it comes to a referendum - which is more likely to be after the return of a hung parliament than an outright Labour victory - the voters may have to be offered a broader range of options than the Labour Party would now like.
It is rather harder to draw conclusions from the latest twist in the party leadership's discussion of its internal affairs. Mr Smith has been saying for months that he wants to replace the old system, in which the bosses of big trade unions exert considerable influence over the selection both of Labour MPs and of the Labour leader at conference, with a new system in which Labour-voting trade unionists become proper individual members of the party in return for an extra payment on top of the levy they already contribute through their unions.
The discussion at the NEC meeting appears to make it more likely that this year's Labour Party conference will back Mr Smith's view. If the conference does so, it will be not a moment too soon. But if Labour hopes to achieve full political respectability, it must go further still: the one-member-one-vote principle should apply not only to the selection of Labour MPs inside local constituency parties and the choice of the party's leader at conference, but also to the way in which the party decides the contents of its manifesto. British voters will rightly be suspicious of Labour until this reform is put into effect.Reuse content