Who should make the concessions to appease the AV rebels? Cameron or Clegg?

The honeymoon has been spoilt by a bout of food poisoning: Tory dining clubs have decided to obstruct the AV bill. More than 50 Tory MPs will rebel because they believe the referendum should be held on a day other than May 5th and that the referendum should not be binding unless turnout exceeds an agreed minimum. Labour, already masters at opposition, will oppose the bill on the grounds that it includes changes to electoral boundaries – a reform that would lessen the in-built bias in favour of Labour, but which it haughtily considers ‘gerrymandering’.

For the sake of the coalition, Cameron owes it to Clegg to at least deliver a referendum, so he must quash this backbench dissent.  It won’t be a case of rounding-up the usual suspects; the rebellion has spread to the Tory left and loyalists – Richard Ottaway and Robin Walker have both signed. With Labour in opportunistic support, Bernard Jenkin, leader of the Tory rebellion, has the numbers to derail the bill.