The press would be given advanced briefing notes so that the content is out there at the same time as the speech is going out. That's done to reinforce the message.
I think he's not suggesting they morph into present day "Tories" but that since there is presently little to choose between both parties that moving to the right may pick up additional votes. Blair successfully tried much the same a while ago.
Though how he'd sell that were it to work isn't clear. If he stuck to it it'd annoy traditional voters, if he abandoned it he'd be out on his ear the following GE (if he hadn't already been deposed as leader by then).