We present a method of electrochemically tuning the threshold intensity of the amplified spontaneous emission (ASE) of a semiconducting polymer thin film. This can be achieved in close contact with a conducting polymer electrode (PEDOT:PSS), if the latter is electrochemically tuned to an optically transparent redox state for the emitted wavelength of interest. This electrical switch between ASE and fluorescence hints that a new route to achieve electrically pumped laser is by combining an electrochemical device with a lasing conjugated polymer.