You may well have seen the coordinated media campaign recently.
This is a crude and rather blunt attempt to force the Governments hand as it finalises SDSR 2015, the figure refers to personnel needed to man both of the new aircraft carriers fully and simultaneously, something that has not yet been decided.
The oft-repeated current position is that the new carriers will both be brought into service to ensure continuous availability of one of them. The Government have been deliberately vague whether this means two in service at the same time, or two in service so as to ensure availability of one.
By creating the headline that the Royal Navy is short of personnel to man them both at the same time it is obviously hoped that this will become the de-facto position.
TheSDSR run up has actually been rather bereft of this kind of thing, personally, I don’t think it helps anyone.