Richard,
Should be easy enough to check out. Have someone push back and forth on the steering wheel while you observe what is happening under the hood (bonnet). If all the play is from the rubber flex joint back to the steering wheel, then you need to get under the dash and check out the brackets securing the column. Believe it or not, a lot of sideways torque is put on this area over the years to get out of the car, especially if the repeat driver is a big person. Not that big a deal to pull all this down and fix it, refer to your Bentley manuel.
If the play comes from your rack, then the rack fell off! Seriously, if the steering is tight, unlikely that the bushes holding the rack down are that worn. Never did like aluminum brackets, transmits every road bump right to your hands.
Bill