All lined up and ready to go, but no take-off clearance and no word from the controller.
If you think you might have been forgotten
"G-AB lined up"
usually produces something along the lines of
"G-AB standby" (ie, shut up I'm busy)
"G-AB hold your position" (ie, no I haven't forgotten you)
"G-AB clear take off" (ie, whoops, sorry)