Thanks John. Looking directly at the prongs of the plug (not from the back). There is an L on the left next to the left hand prong.
The plug is sealed up so I can't get to the wires within the plug. The fuse has been tested and is fine.
Please forgive my elementary question but I'm quite young and learning new DIY stuff every day.
Found a plug in electric mower being given away free - think it's just got a faulty power cable.
Tested cable resistance with multimeter by putting red probe on bottom left plug prong and black...