Thanks one and all for your prompt replies :)
Particular thanks to RF lighting/OwainDIYer - your solution worked perfectly.
The left hand cable contained the permanent live from the ceiling rose.
This was a like for like replacement switch, but my kitchen fitter did not make a note of...
I am having trouble wiring a replacement 2-gang switch in my kitchen. Any help would be much appreciated!
I need 2 separate lights working independently. Left hand cable (see photo) goes to ceiling lights (red, blue, yellow, earth) and right hand cable goes to under cabinet lighting...