Dave Liquorice wrote:

About 1.0-1.5mm diameter would probably be fine.


A quick look on RS shows 500m of 1/0.8mm at £26.72 + VAT code 183-9231
for white also available in blue or brown.


I don't see how any thin wire can satisfy "Strong enough to cope with
being laid on the ground outdoors, and then generally trodden on and
mowed over". I don't think even CAT5 or T&E can withstand these
conditions long term.


--
Grunff