Have I read this correctly?

[ban-all-sheds]

my local authority (Hull CC) says they need test certificates, so can i challange this?

Absolutely you can.

can an untested circuit still be deamed as safe and recieve the certificate back from the LABC?

That's down to them. I would hope not, but...

The key thing to remember is that the council cannot demand that you provide a test certificate - they have no legal authority to do that, and this has been pointed out to them by the ODPM.

If they want the electrical work tested and certified then they must do that themselves - that is what their fee is for!