UK Controlled Airspace is complex and congested; traffic is often oriented on the airway in certain directions or flows.
Therefore, if able, pilots should remain on the assigned route or track whilst carrying out the emergency descent; unless to do so otherwise would endanger the aircraft.
If a turn away from an assigned route or track is initiated, pilots should note that they may not be aware of traffic in their proximity (especially if flying on an assigned heading): nor of aircraft below them, not on the selected frequency, in adjacent airspace sectors. However, it is ultimately the pilot's responsibility to take the action most appropriate in the circumstances.