More than 30,000 homes in Norfolk, Suffolk and Cambridgeshire remain without electricity after high winds from Storm Doris brought trees down on to power lines.
And some supplies may not be restored until Froday afternoon.
At 9.10pm - the latest update given by UK Power Networks - 18,720 homes in Norfolk, 10,080 homes in Suffolk and 2677 in Cambridgeshire - were without power.
The company's website had estimated times for power to be restored, which ranged from midnight on Thursday to 3.30pm on Friday.
Among the areas with the latest estimated restoration times were postcodes NR1 4, NR11 8, IP23 8, IP25 6, IP25 7, IP25 7, NR13 3, NR15 2, NR16 2, NR17 1, NR19 1, NR20 3, NR22 6, NR25 6, NR29 5, NR30 5, NR33 8, NR34 7, NR35 1, NR35 2, NR5, NR8 5 and NR9 3.
Extra staff have been drafted in to deal with the problems.
UK Power Networks said that supplies have been affected by the severe weather across parts of the East of England and South East electricity network.
The company apologised to customers affected and said it was working to restore supplies.
A spokesperson for UK Power Networks said: 'Power supplies have been affected by the severe weather across parts of the East of England and South East electricity network and we have engineers working to restore supplies as quickly as possible.
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