It's not clear that broadcasting impartiality laws are being violated if Cameron refuses to take part. The broadcasters would have offered him completely equal opportunity to defend his ideas that he's then refused. And, yes, despite your obsession with partisanship, if Miliband was refusing to take part in the debates then I'd support empty-chairing him too.
See, I wouldn't support empty chairing milliband either. It gives the broadcasters too much power to dictate and makes the process to easy to manipulate, as both milliband and Cameron have tried to do.
The debates were a vibrant and successful last time and should feature this time. It's true that the broadcasters have fumbled it this time, and we need an independent body to decide the format for future elections, but Cameron is clearly and deliberately playing silly with this. Honestly, the 4:3:2 option originally aired was the best option put forward so it's a pity that didn't fly in the end.
No, it should have been 5:3:2, there has never been any reason to include ukip without including the greens as both stand nationally and have a similar parliamentary presence.
If it had been 5:3:2 at the start, I would be sharing the exasperation at them not going ahead. For me though, any doubt that the attempt to bias the panel was simple incompetence was removed when the broadcasters did the same thing a second time by ignoring the larger dup and including the snow and plaid leaders.