It is true that, largely as a result of their cavalier attitude to expenses, the reputation of politicians in the eyes of the electorate is at an all-time low, and anything that could help restore even a modicum of faith in democracy would be welcome.
However, we must be suspicious of the Prime Minister's motives, as he has been opposed to any form of "proportional" elections throughout most of his political life and was far from enthusiastic about the additional member system adopted for Holyrood.
Firstly, where is the evidence that AV would restore trust in politicians? Ensuring that a constituency MP has the support of more than 50 per cent of their electorate is unlikely, of itself, to achieve that aim.
Secondly, whilst AV has the advantage of retaining a link between an MP and his or her constituency, it does not result in the number of seats held by each party equating to the votes cast for it, so it is not a proportional system.
Thirdly, it seems more than a coincidence that the Prime Minister is backing AV – seen as a first step towards fundamental change to the Westminster voting system – at a time when Labour may need the support of the Liberal Democrats, the champions of electoral reform, to retain power.