Séan Connolly wrote:
Actually I have one wall that is lath and plaster as well (basically a
partition wall), on which the plaster is pretty shagged. Would the same
apply, just remove the whole lot and put up a new partition wall ?

If it's that bad, remove the P&L, fix up any cabling you
need to do, ensuring that it can be pulled through to
replace in future if need be, and replace the P&L with
two layers of 1/2" PB.