A ceiling panel support system including: a ceiling panel having an elongate extent in a longitudinal direction and an elongate support portion from which the panel can be suspended, the support portion having an elongate support channel facing outwardly from the panel, the elongate support channel having a pair of opposing lips (24, 26) defining an elongate opening into the elongate support channel, and the opposing lips (24, 26) having, respectively, inwardly facing surfaces (24a, 26a); and a mounting bracket having a main body to be suspended by a carrier, a holding part configured to be housed within the elongate support channel behind and configured to engage with the inwardly facing surfaces (24a, 26a) of the opposing lips (24, 26), and a leg configured to extend from the main body to the holding part between the opposing lips (24, 26); wherein: the main body of the mounting bracket includes lower surfaces on either side of the leg configured to face the support portion when the mounting bracket is fitted to the ceiling panel with the holding part housed within the elongate support channel characterised in that: the system further includes a securing member having a base surface configured to engage with the support portion and a top surface configured to engage with the lower surfaces of the mounting bracket, the securing member is configured to be inserted between the support portion and the lower surfaces of the main body of the mounting bracket, and, with the securing member so inserted, the base surface and the top surface are configured to provide respective opposing forces on the support portion and the lower surfaces of the mounting bracket respectively, thereby pressing the holding part against the inwardly facing surfaces (24a, 26a) of the opening lips (24, 26)and securing the mounting bracket frictionally along the elongate extent of the panel. a ceiling panel having an elongate extent in a longitudinal direction and an elongate support portion from which the panel can be suspended, the support portion having an elongate support channel facing outwardly from the panel, the elongate support channel having a pair of opposing lips (24, 26) defining an elongate opening into the elongate support channel, and the opposing lips (24, 26) having, respectively, inwardly facing surfaces (24a, 26a); and a mounting bracket having a main body to be suspended by a carrier, a holding part configured to be housed within the elongate support channel behind and configured to engage with the inwardly facing surfaces (24a, 26a) of the opposing lips (24, 26), and a leg configured to extend from the main body to the holding part between the opposing lips (24, 26); wherein: the main body of the mounting bracket includes lower surfaces on either side of the leg configured to face the support portion when the mounting bracket is fitted to the ceiling panel with the holding part housed within the elongate support channel characterised in that: the system further includes a securing member having a base surface configured to engage with the support portion and a top surface configured to engage with the lower surfaces of the mounting bracket, the securing member is configured to be inserted between the support portion and the lower surfaces of the main body of the mounting bracket, and, with the securing member so inserted, the base surface and the top surface are configured to provide respective opposing forces on the support portion and the lower surfaces of the mounting bracket respectively, thereby pressing the holding part against the inwardly facing surfaces (24a, 26a) of the opening lips (24, 26)and securing the mounting bracket frictionally along the elongate extent of the panel.