"I am going to saying to every MP 'look the House of Commons ought to be smaller, less expensive and we ought to have seats which are exactly the same size'," he said.
"I think everyone should come forward and vote for that proposal because it is a very sensible proposal and it will be put forward."
So, with Clegg's party ready to rebel, is there any chance of Cameron getting his way? Unless the Prime Minister knows something we don't, the answer is no. Most of the nationalist parties, including the DUP, which holds eight seats, are publicly opposed to the changes and are unlikely to be easily bought off. In addition, at least a handful of Tories can be expected to vote against the reforms as three of the party's Cornish MPs (George Eustace, Sheryll Murray and Sarah Newton) previously did. Without the support of the Lib Dems, there is no majority to be found.
Cameron's hope, presumably, is that Clegg, who previously declared that "there can be no justification for maintaining the current inequality between constituencies and voters across the country", can be persuaded to renege on his opposition. But with the Deputy Prime Minister now publicly pledged to vote against the changes, this would surely be a humiliation too far.