Abstract: Fluorescent lamp comprising a glass discharge vessel (2) in which an ionizable and vaporizable filling is present, which discharge vessel is on two sides provided with a tubular end portion including a glass stem, wherein an exhaust tube (6) extends axially outwardly from said stem for supplying and/or discharging gases during production of the lamp, wherein a main electrode (8) extends axially inwardly through the stem for generating and maintaining a discharge in the discharge vessel, and wherein the lamp comprises means including an auxiliary electrode (15) for controlling the pressure of said filling in the vapor phase, despite changes in temperature thereof, with the special feature that said auxiliary electrode is located on at least one end portion for generating and maintaining an auxiliary discharge between the main electrode and the auxiliary electrode.