Hi az
I would contact the DWP near the dead line and ask for an extension, explain that a holiday has been booked and you will not be back until 14th August. DWP should be able to give you a two week extension, if this extension is cutting it close, contact DWP again and ask for another, make sure you ask for an extension before the time runs out..
Enjoy your holiday
Gary
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
