I'd suspect something in the pedal assembly - if I'm not mistaken.
I just check the manual - on a LHD vehicle the clutch cable does not connect directly to the pedal as it does on a RHD vehicle - your pedal turns a shaft, and the other end of the shaft has a lever on it that moves the cable. This lever is on the right side of the brake pedal - and from the looks of it, the shaft has a squared portion that the lever sits on and is held with a nut. I suspect that lever may be loose, or the squared hole in it may have started to round off.
At some point I think I've heard of this being welded - but as I mentioned, this is only on LHD vehicles, so I've never actually seen it.