That is NOT an Earth cable,. it is the electrical supply cable to you house from the street. It should be supported by clamps to the wall. It should NOT be hanging from the cutout. ( the box with the main electrical fuse )
It appears that the cable gland has become detached from the cutout and the full weight of the cable is now hanging only by the conductors ( Live and Neutral ).
View attachment 219566
This needs urgent attentions from the DNO ( District Network Operator ) who are responsible for the cable and the cutout.
Use this to find your DNO
https://www.energynetworks.org/operating-the-networks/whos-my-network-operator and contact them to arrange for the cable to be made safe.
DO NOT attempt any DIY on this cable,