A method and apparatus for selecting cells in a mobile telecommunications system, the system comprising a network of a plurality of cells of a Universal Mobile Telecommunications Systems (UMTS) and a network of a plurality of cells of a second Radio Access Technology (RAT), the method comprising, at a user equipment device: when in UMTS mode, flagging in a neighbouring cell list stored on the user equipment device information for a cell of a second RAT which is known to be unsuitable for selection. Information from the neighbouring cell list information for the flagged cell may be removed, in particular for a limited period of time.