Thanks. So if I twist the wires together so they can't come apart and then solder, that should be fine? There's enough earth showing for me to do that.
I am replacing a double-insulated wall light with one requiring an earth. There is an earth wire in the cable but it has been cut too short to fit to the light. Would I be OK to solder some wire to the existing earth so that it will reach the fitting point inside the new light?