He will campaign for 24 hours through Tuesday night.
There may be a theme developing here - as we spotted several late breaking policies missing from his essay crisis manifesto.
But does it really work? How many undecided, floating voters can he reach, say, between 1am and 5am for example?
The Telegraph suggests there might be crack of dawn opportunities at Billingsgate Market or Spitalfields.
Mr Cameron's all-night blitz is expected to see him visit fishermen, bakers and florists who work in the early hours of the morning.
There is some sense in that. But Next Left is unconvinced that this stands up the "all night campaign" claim. We will want to see the 2am, 3am and 4am timesheets of what he was up to.
Telephone canvassing is probably a no-go. Would there be greater risks in disrupting hard-pressed accident and emergency staff; catching mini-cab drivers or kebab vendors in university towns, or perhaps trying to engage the hardened end of night clubbers in rational political argument?
So will the Tories commit to letting us all know whether it really was an all night campaign - or whether a quick kip in the early hours ended up making more sense?
After all, transparency engenders trust. And that would stop the cynics dismissing Cameron's all night campaign as a mere media stunt.