In a minority of Councils there are all-out elections every four years. This is the case in London, and last year on the same day as the General Election the 32 London boroughs held elections, usually for three councillors in each of their wards. Electors are told they can vote with crosses for up to three candidates that are listed alphabetically by surname.
Most of the parties nominated three candidates in each ward and encouraged their supporters to use all three of their votes for their listed candidates. No party campaigned on the principle that voters can and should vote for candidates from different parties on the same ballot paper. However, although no party made this suggestion, thousands of voters across London made the decision to split their votes for candidates for two or even three parties.
In my own ward of West Hampstead in the London Borough of Camden voters had to make a single choice for their preferred MP, but on the same day and within seconds of completing their ballot in the parliamentary election, many voted for a "pick and mix" slate of Council candidates. In West Hampstead our Liberal Democrat campaign managed to secure 1,316 supporters who voted for the three Lib Dem candidates. But the counting of the Council election voting papers then went into the more complex procedure of counting the split ballots, where voters had decided to vote for a combination of candidates (or only one or two) which did not match the party slates.
On the split ballots I received an additional 745 votes which placed me at the top of the poll with 2,061. But that means around 36% of those who voted for me also voted for a candidate from another party. And don't forget this was at a time when every party was saying "only vote for us". No one was advocating splitting votes. No one mentioned this in conversations on doorsteps or in campaign leaflets. This was the electors making their own sophisticated judgements about the mix of parties they preferred.
I think this demonstrates there is a clear appetite for voters to choose to vote preferentially for candidates from different parties. Just think what would happen when candidates in an AV election had to reach out to attract "2nd preference" votes from other parties' supporters.
The appetite for preferential voting is already there and it's about time the politicians learned a lesson from the voters.