There have been a few posts on this forum over the years where the subject of 5A trailing sockets has come up. At the time my answer was that permaplug still seem to do them but finding a supplier that actually gave stock indications and had the ability to buy online was almost impossible.
Anyway much to my surprise when browsing my new CPC catalogue (searching for 5A BS546 on CPCs site didn't and still doesn't find them) I found them listed, price was kinda high though. http://cpc.farnell.com/masterplug/els5b/trailing-socket-5a-3-pin-round/dp/PL14140 . What was more interesting though was that they listed a manufacturers part number (something I had not previously been able to track down).
I googled the part number and found that a couple of vendors I have used in the past for computer related stuff had them at far more reasonable prices.
http://www.misco.co.uk/product/2154...Heavy-Duty-5A-Round-Pin-Trailing-Socket-Black
http://www.uk.insight.com/en-gb/productinfo/surge-protectors/0002327237
Anyway much to my surprise when browsing my new CPC catalogue (searching for 5A BS546 on CPCs site didn't and still doesn't find them) I found them listed, price was kinda high though. http://cpc.farnell.com/masterplug/els5b/trailing-socket-5a-3-pin-round/dp/PL14140 . What was more interesting though was that they listed a manufacturers part number (something I had not previously been able to track down).
I googled the part number and found that a couple of vendors I have used in the past for computer related stuff had them at far more reasonable prices.
http://www.misco.co.uk/product/2154...Heavy-Duty-5A-Round-Pin-Trailing-Socket-Black
http://www.uk.insight.com/en-gb/productinfo/surge-protectors/0002327237