More than 10,000 properties in south-east London and Kent are still without electricity, three days after a vandalism attack caused power cuts.
EDF Energy said it had managed to restore full or temporary supplies to 84,000 of the 94,000 customers that had been affected.
Homes and businesses in Dartford, Crayford, Bexleyheath, Erith and Orpington have been hit.
EDF Energy said it hoped to have power fully restored by Thursday morning.
Police are investigating the fire damage to power cables in Dartford on Monday.
Generators were brought in from as far as Scotland, Bristol and Great Yarmouth, and set up at 46 locations, including a number of care homes across the Dartford area.
Shops, banks and petrol stations have been hit
Engineers have also been switching to power supplies on other regional networks to divert electricity to the south-east London grid.
The British Red Cross have visited a number of vulnerable customers to offer advice and support.
Bob Lane, EDF Energy's Director of Network operations, said: "We continue to work as quickly as is safely possible to restore power to all our customers.
"We are also working with Kent Police, who are investigating a number of possible criminal causes of the incident.
"From our investigation we believe two substantial locks on metal doors at either end of the cable bridge were cut with heavy duty tools."
He added: "Because of the extent of the damage and complexity of the repairs, it is not possible to be completely accurate but EDF Energy Networks hopes that power will be restored to remaining customers not already back on supply, either permanently or temporarily, tonight."
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