Interesting, thanks Keith, it appears that a lot of bod's are still under that impression. I'll pass that onNot so, it's historical. The supply in France used to be 2 phases out of 3 for domestic use giving 220 volts across the 2 phases, so both conductors were live. When the system was modernised it became 220 and later 240 volts per phase and the neutral was introduced, however double pole switches and isolators were retained and when MCBs were introduced the regs required that they were also double pole. Many French Sparkies still ignore the regs and you may find the neutral on either side of a socket