Westminster's most promising MP had this to say about AV:
AV would make hung Parliaments more likely. As we have seen, a coalition agreement must then be formed through rapid haggling after the public have voted. That reduces democratic legitimacy in comparison to a clear mandate for a particular manifesto.
Under AV, candidates would have to court the second preference of those likely to vote for the most unpopular candidates first. This seems to me a perverse situation which is likely to produce odd, manufactured pledges from otherwise mainstream candidates.
Only three countries in the world use this system for their parliamentary elections: Fiji, Australia, and Papua New Guinea. An opinion poll taken after the Australian election, an election which brought their country to a political standstill for weeks not days, showed that 57% would change their system to a UK-style First-Past-the-Post (FPTP) system, while only 37% would retain AV.