Gness, They will disconnect you if there is a power generation shortage. When the demand for power is more than the maximum generating capacity , ordinary homes will be disconnected to save electricity for essential users like hospitals ,vital industry and military bases.
A smart meter means they can disconnect you direct from the power companies computer ,instead of having to come to your house and disconnect the meter. It is called Load shedding or Load management . Those with smart meters will be the first to be disconnected . This is why the power suppliers are so desperate to get smart meters in all homes. The electricity supply situation is going to get worse as old power stations reach the end of their useful life. It will not improve until the UK's new generation of French/Chinese built nuclear stations are all online in 10 to 25 years.