Cameron gave a master class in how to run a press conference

Nick Wood's High Noon column.

Not so long ago every day in an election campaign began with a morning press conference hosted by a senior figure - usually the party leader.

Not so today. In fact, by my reckoning, it took until today, 20 days after the election was called, for David Cameron to face the media in time-honoured fashion. Cameron was in London at party HQ. Nick Clegg, meanwhile, was in Edinburgh trying to win support for the Lib Dems north of the border.

The contrast was striking. Cameron gave a master class in message discipline, deftly turning every question back onto his main point, that a vote for Clegg was a vote for five more years of Gordon Brown.

Clegg has an endearing, but ultimately amateurish tendency to answer the question, often at great length. He should watch a recording of Cameron's assured and disciplined performance to get a stronger sense of how to stay on message. Cameron should do more of these conferences. He's good at them and it gives him credibility with the media.

Both men were essentially being asked the same question - what would happen in the event of a hung Parliament? Dave's plan for a greener Britain through the innovation of new parks created by local communities was predictably ignored by the press - as was Clegg's renewed assault on the bankers.

Clegg's readiness to think aloud has already sowed some confusion. Apparently, he won't do a deal with Gordon Brown if Labour come second in seats but third in terms of the popular vote. But is is less clear whether he would do a deal with Labour if Mandelson and Co ditched Brown as leader and installed someone more PR-friendly, such as Alan Johnson.

The media was out to get Cameron over whether he would contemplate ditching the first past the post system for some form of PR. He made abundantly clear his distaste for PR but smoothly avoided actually ruling out talking to Clegg post election about changing the voting system.

He was right to do so. First, Cameron is back on his love-bomb the Lib Dems ticket, going on at some length about how green, local and energy efficient is the new-look Tory party. Fine in so far as it goes but the objection remains that the Lib Dem surge has little to do with Lib Dem policy and a lot to do with Clegg posing outrageously as the Mr Clean of a rotten Parliament.

Cameron should beat the drum yet more loudly about the ghastly spectre of a hung Parliament.

Second, no politician worth his salt rules out anything unless he has to. Cameron wants room for manoeuvre in a hung Parliament. This is understandable. But the weight of Tory opinion against PR in any form is so strong that he may have to kill off the prospect completely within the new few days.

Nick Wood of Media Intelligence Partners.