Anyone any ideas on what would cause all the electrics to intermittently cut out? l can hear the solenoids clicking and the gauges all flick as if the power is being cut from them. I've checked out all the earths, and looked for shorting wires but not found anything!

Could be the Alternater or dizzy cap

take all the junk off your ingnition key. and try again. and also check the battery terminals are really tight, peugeot use crappy termonal connectors, which look good, but dont actually clamp