If you're already working a unit then you should make your requirements known to them i.e. as a pan. In this case as you're in an airway then tell the controller.
Apart from being under mandatory radar control inside an airway the controller already has all your flight details to hand and they know where you are. They also have rapid access to the information you require plus a line to D&D to get any info they don't have.
If you 'freecall' D&D on 121.5 then they would require to extract all the flight details from you and locate you. Similarly FIS/FIR but if you're in emergency then D&D exist purely to serve you, it is their function.
Thought all this was in the UK AIP??!!