Today is said to be "crunch time" in the House of Lords, with an attempt to put an end to Labour's efforts to scupper the referendum bill by filibustering. As I understand it Labour's publicised objection to the bill is not so much to electoral reform as to the reduction in the number of parliamentary constituencies for the Commons (although I suspect this may just be a convenient cover from their unreconstructed die hards.)
However, if their publicised objection is genuine I have some sympathy for them. The case for electoral reform, even the feeble AV version, is overwhelming, whereas the case for a reduction in the number of constituencies is much more debatable. I think Liberal Democrats proposed this as a rather childish and ill thought out knee-jerk reaction to the expenses scandal, and am sure that the Tory motive is to "adjust" (I avoid the term "gerrymander") the boundaries to make life harder for Labour.
When I first started serious study of British politics in the 1950s there was a pronounced bias in the electoral system toward the Conservatives, as Labour piled up huge majorities in densely populated urban areas, and the Tories smaller ones in more thinly populated rural constituencies, but that didn't seem to worry them and they never did anything about it. The size of constituencies has to be a compromise between population size and geographic size, and would probably be easier if we had multi-member constituencies. Certainly one of the less well appreciated advantages of STV is that changes in boundaries would need to be less frequent, as interim adjustments can be made by simply adding or taking away a representative.
An argument in favour of reducing the number of constituencies is that modern communications make it easier for MPs to keep in contact with a more widely spread electorate than in the days when they reached outlaying areas on horseback. Against is the fact that there are now such a large number of MPs on the government payroll that we are rather short of numbers in carrying out the vital task of holding the government to account.
So there are really two issues in the bill, one very much more arguable than the other. There is no really hurry about changing the number of constituencies, so from the electoral reformers' point of view the best outcome in the Hose of Lords today would be for the coalition to give in on the marrying of the two issues and allow separate separate bills. That would remove Labour's excuse for opposing the referendum, the support of which was, of course, one of their manifesto promises. Fingers crossed.