A method and a radio base station for interleaving control channel data to be transmitted in a telecommunications system are described. The method comprises grouping the control channel elements CCE1-CCEn into a first order of control channel symbol groups, determining a number of available symbol group positions of control channel transmission resources, adding symbol groups comprising “dummy” values or zeros to the first order of control channel symbol groups, interleaving the first order of the control channel symbol groups resulting in an a second order, cyclic shifting the second order and mapping the cyclic shifted second order of control channel symbol groups to the control channel transmission resources.