Speedbird,
I'm not sure of the UK situation, but in Canada, the CPL required a 300 nm radius trip, i.e. a 600 nm round trip. Of course, if you flew with someone else, they might be able to do the return journey. As from the sounds of things in the UK, you also had to include 3 full stop landings as well .........
I could be wrong, and someone in the know will no doubt in the fullness of time validate this !!
Good luck.
CG