Well i had my physio appointment on Friday and i came away with lots of stretches to do and instruction to reduce my ride distances for a while.
From my own research into the knee problem, i believe i started the training by going too hard too fast. I should have kept in my mind that its been atleast 5 or 6 years since the last time i cycled. I have been stretching everyday over the weekend. On Sunday i tried a short ride (7 miles) and got home with no obvious signs of the injury coming back. Today i didnt get chance for a ride, instead i put my bike on the trainer and used that for a while (like a rolling road for cycles). Again no sign of pain yet. I will need to get out cycling more often now, but for shorter distances. I will gradually build the distance until i can again do longer weekend rides. I just need to keep stretching, build the distance slowly and stop if the pain comes back.
It leaves me still concerned about the ride, but with a view that atleast i have a plan to try and overcome it, even if it does leave me with no room to spare in terms of training time before the ride. I just hope i can get back to doing more distance pretty soon.