I suppose you could do that and it'd probably work, although I'm not saying you should do it - the question being "what is it?"; it's not part of the fixed wiring and it's not an appliance, just some hideous creation which is stuck in limbo somewhere in between.
If you're going to wire sockets with flex you should terminate the ends with bootlace ferrules in accordance with 526.8.1 which is about "avoiding separation of individual wires in multiwire, fine wire, or very fine wire conductors", not about daisy chaining sockets and plugging them in somewhere.
Obviously the ideal solution would be to get the existing socket moved or another one added in accordance with the appropriate regs, esp EAWR 1989 regulations 10 ("Where necessary to prevent danger, every joint and connection in a system shall be mechanically and electrically suitable for use")
and regulation 16 ("No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or, where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work.")
A desire to save money is not generally considered a defence for contravening the EAWR (the law).