The first thing I would note is that there is red and black insulation on the conductors. Either this installation is quite old indeed (red & black went out in about the '80s off the top of my head) or was wired in incorrect colours.
As for minor works these do not have to be certified, but if a Registered Electrical Contractor (REC) carries out the work then the customer has a right to request that a Cert No. 3 is issued with the "minor works" box ticked. Cert No. 3 is the certificate for works which do not require DSO involvement. (Prior to the introduction of Cert No. 3 there was a "Declaration of Compliance with ET101 for Minor Electrical Installation Works".)
But as the OP has stated that he will involve a REC to repair this then the REC should be able to advise on the best course of action. Certainly with the obvious damage I would be expecting that length of cable to be replaced - ideally back to the outlet it comes from.
One thing that has me confused is with the age of the installation (taking account of the wiring colours) why the socket-outlet is at that height. New work must be within the range of 400mm to 1200mm - perhaps it is lower there and I've just misjudged from the picture. If the socket-outlet is rewired it will have to be set at this height.