pretty common problem this time of year mate.
over time the outter protective skin on the handbrake cable perishes and lets water in. when your car is stood this freezes and grips the handbrake cable, causing the cable to get held in one position, typically frozen on as this is when the car is cold.
if you give it long enough and let the car warm up the exhaust heat should defrost the cable and you can carry on your way, but it will happen again when you next leave the car stood.
the usual trick for this is leaving the car parked in gear with handbrake off, however I dont know if this is possible with the selespeed.
ultimately the best way to stop this is to replace the handbrake cable.