Just imagine the conversation in the Labour leaders’ office when the call came in.
“It’s The Sun. They’re handing out a free edition to every home in England -- does Ed want to have his picture taken holding it up?”
“But of course” comes the reply, “money can’t buy that kind of publicity”.
And then, two days later...
To be fair to Ed, he wasn't alone. David Cameron and Nick Clegg posed with the paper as well.
But when you're leader of the Labour Party, you can't go around smiling (however uncomfortably) and holding up copies of The Sun. You just can't.
Let's leave aside the apparent hypocrisy of endorsing a newspaper you've spent so much time criticising, and ignoring too the fact this is exactly the kind of "cosying up" behaviour you've condemned in the entire political class -- it's The Sun, and you're the leader of the party with a lot of MPs in Liverpool.
MPs who are now duty bound to condemn their own leader. True, money can't buy that kind of publicity.
So why did Ed Miliband's advisers let him do it? Well, there are just under half-a-million people in Liverpool, and despite this row many of them will probably still vote Labour next year.
There are 6.7 million Sun readers, who could be exposed to daily ridiculing of Ed Miliband between now and next May.
For all that bravado, Labour still seems scared of The Sun, even though the days when it could claim to turn elections are far behind it, and even though a significant proportion of Sun readers continue to vote Labour, regardless of whatever the paper may throw at the party.
No wonder Ed looked so very uncomfortable holding up that paper...