If Britain votes Yes to the Alternative Vote (AV), the next election will be fought under AV. Unless the new gerrymandered constituency boundaries have not yet been agreed. The boundary review will take at least until 2013, and must then be approved by parliament. If the next election were to happen before the new boundaries have been approved, it would be fought under First Past the Post (FPTP) whatever the outcome of next month’s referendum. That would be keep the Coalition together, in government, for a least three more years and probably until 2015. However unpopular the government are. However strong the opposition to their next two budgets. However much discomfort some Lib Dems feel about the dismantling of the NHS.
The rules are clearly set out by the Electoral Commission in its referendum guide:
The ‘alternative vote’ system will be used after a review of the boundaries of the area that each MP represents (known as their constituency) is completed. This is due to happen between 2011 and 2013. The review will happen regardless of the outcome of this referendum.
At the end of the review, the UK Parliament will vote on implementing the new boundaries. If the new boundaries are implemented, the ‘alternative vote’ system will be used for all future elections to the House of Commons.
For most Lib Dem MPs, the only hope of surviving the slump in their support will be AV. This will provide a very powerful incentive for them to stay in the Coalition.
For Labour, on the other hand, it is now clear from a YouGov poll for Channel 4 that the Lib Dems’ gain from AV would be Labour’s loss. They predict that under AV, the Lib Dems would win 13 more seats than under FPTP — 29 rather than 16 — whilst Labour would win 13 fewer. The Tory total would be the same although which seats they won would differ. Seats like Harlow would go to the Tories rather than Labour whilst others in the south-west, for example, would be retained by the Lib Dems rather than fall to the Tories.
Why is this the case, when it used to be said that Labour would gain from AV? Because so many people who voted LibDem last time have already transferred their allegiance to Labour, and more of those who will still vote Lib Dem would give their second preference to the Tories than to Labour.
The detailed YouGov results provide much information about second and subsequent preferences, although they predict a rather unrealistic low switch in allegiance in AV first preference votes from FPTP voting intentions — both Labour and Tories, for example, are predicted to retain 96% of their FPTP voters as first preferences which must understate the switch to UKIP and the Greens, for example. The most interesting details are as follows:
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