A cellular communications system is described in which a mobile cellular device can, if necessary, obtain cell measurements for cells contained within a first cell list after it has received a second cell list. The mobile device then reports the cell measurements for cells within both lists so that a best candidate cell is less likely to be discarded in a cell handover procedure. A network node is also disclosed that can receive cell measurements for cells within a first cell list after the node has issued a second cell list. The node then uses the received cell measurement data to control a handover procedure.