Yes the screws are screwed all the way out and yes it did fit the old switch. Will revisit it at the weekend and make sure I'm not missing something. Will take a picture too if I can't work it out. Thanks for the help.
That's what I did to start with and couldn't get them to fit. So I removed everything and tried a "test" fit by just trying to push the cable ends straight into the terminals to make sure I wasn't imagining they wouldn't fit and I still could not get the cable into the terminals :x
Whilst...
The feed is what I assume to be 6mm and the cable from the shower is noticeably larger, 10mm. I think?
When you say "dress" the cable I'm guessing you mean more than just stripping off the outer covering?
Wanted to replace switch as current one is faulty. Purchased Crabtree 2167 Ceiling Shower Switch 50a as it was recommended elsewhere and the fact the it states there is loads of room to take upto 10mm cable was a bonus. However I am struggling to get the cable from the shower to the unit...