Apex domains cannot have CNAME records.
Question and response
Question
dig binknet.uk. NS
Answer
binknet.uk. 5 NS ns0.server.fido.net.
binknet.uk. 5 NS ns2.server.fido.net.
binknet.uk. 5 NS ns1.server.fido.net.
binknet.uk. 5 NS ns4.server.fido.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0