If the referendum on AV was lost, Nick Clegg would face loud and sustained calls from his party to pull out of the coalition. To most Liberal Democrats, it would be unclear what they were getting out of the Coalition if they weren’t getting a change to the voting system. For this reason, there’s considerable chatter in Westminster that the Tory leadership while nominally opposing a change, will not campaign hard against it. In other words, they’d be prepared to see the AV referendum pass if that was what it took to keep the Coalition together.
It’ll be interesting to see if there is any backbench reaction to Cameron’s comments. Most Tory MPs remain steadfast defenders of first past the post and would want to see the party throw its full weight behind it in the referendum campaign.