I'm getting the occasional one off loud click from the front of car that you can feel through the steering when parking and on full steering lock. The cars only a year and a half old. Is it the CV joint or the steering column. Also although there's no play in the steering wheel at times when driving straight it feels like there's some play in the steering. Does anybody else have this problem. 

Usually if it is the CV joint when on hard lock left or right it would click a lot in rapid succession  click click click click ,not just once and then it would be a bit worn and done  many miles ,at one year old as your car is I would be  very surprised if it was that.

I've had a look at the CV joints and they appear to be ok. I drove around today and only heard the click once when parking. I drove it round in circles on full lock right and left and didn't hear anything.  

I know the early mk7 fiestas had a problem with the universal joint on the steering column (inside the car in between the steering wheel and the bulkhead) . it would be dry and stiff and click, I would have thought they would have made sure in later years the problem was resolved.

When I'm parked and turn the steering wheel left and right I can hear loads of clicks coming from the front right of car 

I think you are going to have to get your head down there whilst someone else turns the steering wheel to see if you can locate it more precisely.

If you jack it up make sure it secure with axle stand etc but if the weight is off it then it probably won't click