<p><span style="color: rgb(33, 33, 33);">During the earliest stages of star formation, the discs around very young protostars can have masses comparable to that of the central protostar. This means that they are susceptible to the growth of the gravitational instability. Initially, this instability will manifest as spiral density waves that can act to transport angular momentum, potentially playing a big role in the accretion of mass onto the central protostar. However, if the instability is sufficiently strong, the spirals can fragment to form bound objects, that could then contract to form giant planets or brown dwarfs. It’s possible that this is the dominant formation scenario for the wide-orbit planets and brown dwarfs that we are now able to directly image. Additionally, the presence of spiral density waves can act to enhance the local density of solids, potentially accelerating the growth of planet building material. In this talk I’ll present our current understanding of self-gravitating protostellar accretion discs, briefly discuss how this phase influences the formation of the protostar itself, and then highlight the various roles it may play in the formation and evolution of planetary-mass bodies.</span></p>