A method of transmitting blocks of data in a wireless telecommunications system in which blocks of data are transmitted a plurality of times. When a first block of data becomes available for transmission an initial selection of transmission resources for a plurality of transmissions of the first block of data in a corresponding plurality of time periods is made, and transmissions of the first block of data are started. While there are still transmissions of the first block of data which remain to be made, a second block of data becomes available for transmission. In response to this, the initial selection of transmission resources for the remaining repeat transmissions of the first block of data is modified to increase the amount of resource available for transmitting the second block of data during the time periods in which repeat transmissions of the first block of data remain to be made.