I'd been out for a drive with my partner today, coming back home on a country road, when I suddenly realised I was having a loss of power and, when I looked at the instruments, I saw that EPC was illuminated.

I found somewhere to stop and looked in the manual and realised that it had gone into Limp Home mode, but after switching off and on again, the fault light cleared and I was able to drive the 25 or so miles home (carefully!) without problems.

I've contacted my local garage using their online form, so I can get them to check the OBD, but if anyone's got any other useful advice, I'd welcome it.

Don't know if this is your issue, but I had the same symptoms a couple of years ago which was caused by a failing turbo actuator (P334A). Got it replaced at a garage and it's been good ever since