Fuel system

A fuel system for use in supplying high pressure fuel to an injector of an internal combustion engine comprises a first fuel pump (12) for supplying fuel at a first injectable pressure level to a first accumulator volume (16), a second fuel pump (14) for supplying fuel at a second injectable pressure to a second accumulator volume (18) and control valve means (25) for selecting which of the first or second accumulator volumes (16; 18) supplies fuel to the injection nozzle.