The hostile environment, the very restricted access geometry, the required spatial resolution and the target accuracy all impose severe constraints on the design of many techniques proposed for spatially resolving ITER plasma parameters. Despite the constraints it appears feasible using LID AR Thomson scattering to make measurements of the electron temperature and density profiles in the ITER core plasma. A generic scheme using reflective optics for the front end is adopted. The scheme uses a folded mirror system positioned inside a shielded labyrinth located in a standard radial port. The same mirror surfaces and vacuum window are used for both the laser input and the collection path. Radial and tangential sight lines are considered. The sight line uses a single 30cm diameter blanket penetration and an exit window of <20cm diameter. The specified spatial resolution of 30cm can be met using existing laser and detector technology. Calculations of the expected accuracy of the temperature measurement are presented for different laser/detector combinations. The results are based on extrapolations from the existing JET LIDAR system and are therefore bounded by the constraints of a realistic optical system. The background to the design will be reviewed and some details of the front end optical design will be presented. Possible methods of obtaining some of the necessary calibration data will also be discussed. The critical outstanding problem for the design is to identify suitable materials which can simultaneously withstand the heat, gamma, neutron and laser beam fluxes.