For a general class of finite element spaces based on local polynomial spaces E with P-p subset of E subset of 2(p) we construct a vertex-edge-cell and point-value oriented interpolation operators that fulfil anisotropic interpolation error estimates.

Using these estimates we prove epsilon-uniform convergence of order p for the Galerkin FEM and the LPSFEM for a singularly perturbed convection-diffusion problem with characteristic boundary layers. (C) 2011 IMACS. Published by Elsevier B.V. All rights reserved.