Earthing for lighting

Hi all,

Just went looking around in my ceiling as i am looking at replacing the lights in our house, and none of the light fittings have earths. It appears to all be run in 2 core flat

My question is would you just run an earth wire to each light fitting or would you run new 2C+E flat to each light fitting?

I am thinking while i am up in the roof, i might as well just re run all the cable and i am trying to justify the cost to the OH

I haven't done a great deal of house bashing so any opinions would be appreciated

Thanks


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