Reduced particle confinement (often refered to as "density pump-out") has been observed in magnetically confined fusion plasma experiments where non-ambipolar particle losses are expected, e.g. in ripple and Resonant Magnetic Field (RMP) experiments [1]. It has been proposed that the so-called "convective cells" or poloidally localised 2D electric fields could be at least partly responsible for the confinement degradation. In this contribution we study the neoclassical particle losses in the presence of an axisymmetric, electrostatic, 2D potential. As a simulation tool for this analysis we use XGC­0 which is a guiding centre following Monte Carlo code developed for resolving neoclassical transport. XGC-0 is able to follow both ions and electrons and it solves the radial electric field self-consistently from the radial current balance. On top of the existing functionality a model for a static 2D gaussian potential was added. We use this set-up a to estimate how large the 2D perturbation has to be to have a non-negligible effect. If found to be relatively modest then more CPU time consuming 2D/3D Poisson equation solving self-consistent codes could be used to together with the loss mechanisms to see whether such poloidal potential variations can exist.