One thing that annoys me when talking about voting reform is the detractors that argue “If there are more parties there will be more hung parliaments.”
The idea of needing to form a coalition makes no sense to me. Why not just force parliament to elect the prime minister at a certain date with a reasonable voting method? To go a bit further, why not just have parliament elect each member of the cabinet? The role of the PM could be to settle potential conflicts within the cabinet and dismiss a cabinet member with majority support from parliament.
Do you see any downsides to this? I think that it would allow for a more fluid set of alliances and create a government that more accurately reflects parliament as a whole.
If we were to do this, what voting method should be used? I think the best method is to rank and score the candidates. If there is a Condorcet winner, elect him; if there isn't, elect the guy with the greatest total score. Scores would be restricted in the following manner:
1) Maximum score would be 3 * number of candidates.
2) MPs would not be able to score a candidate higher than a candidate he ranked higher.
3) Minimum score to give a candidate would be 3* [number of candidates-candidate rank]