Method and apparatus for controlling fuel pressure in a gaseous fuelled internal combustion engine

A method for controlling fuel pressure in an internal combustion engine consuming a gaseous fuel and a liquid fuel comprises steps of determining a gaseous fuel pressure target value as a function of an engine operating condition; pressurizing the liquid fuel to a liquid fuel pressure based on the gaseous fuel pressure target value; and regulating gaseous fuel pressure from the liquid fuel pressure; such that the gaseous fuel pressure equals the gaseous fuel pressure target value to within a predetermined range of tolerance.