The position control of the JET plasma is based on the measurement of poloidal flux differences between desired inboard and outboard and between symmetric top and bottom reference positions inside the vessel. The error signals, assisted by preprogrammed functions, control the output voltages of 50Hz thyristor power supplies which are connected to vertical and radial poloidal field coils. The precision achieved is about 1cm and plasmas with elongation ratio b/a1.6 can be stabilised in the vertical direction. The plasma current is controlled by appropriate preprogramming of the excitation voltage of a 2.6G Joule flywheel generator convertor. Plasma current feedback will be applied in future experiments. The control system is built with analogue electronics, but control functions are issued from CODAS which is the JET control and data acquisition system.