Where are you storing your petrol, Modeste? If it's within a domestic garage, or within 6 metres of any building, the legal limit is two ten-litre metal containers or two 5-litre plastic containers.
If you want to store more petrol than that you must notify the Petroleum Licensing Authority and store the petrol in accordance with the Petroleum Spirit (Motor Vehicles etc.) Regulations 1929.
Failure to comply with the relevant Regulations is a serious offence.
This ban on petrol being sold in cans was announced a couple of nights ago - it is because of petrol bomb risk. Hopefully it will be lifted in a few days' time, I didn't hear that it was a permanent ban.