This is a no-brainer really, if you have 700 potential non conforming supply terminations in what are, general public service areas.
Your clients best bet, is to hire the services of a Chartered Electrical Engineer to conduct a survey and report. Include any photo's and manufacturers published data, and pursue his claim for the required remedial work, or compensation award, sufficient to cover his costs and for this work to be carried out by a third party.
This solicitors letter your client received, is just a 30 quid (or whatever it costs these days) scare letter and not even worth a second thought legally, but is worth considering as further evidence in your clients claim!!
It's either your client claiming against the initial installer, or your client footing the remedial costs himself. One way or another the work needs processing, and preferably sooner rather than later, where public liability is concerned...
