More than 250 Hastings homes are without power and a Tesco Extra store has been forced to close due to a power cut.
According to UK Power Networks, 256 homes in the TN34 2 and TN34 3 post codes have been affected.
Tesco Express, in Havelock Road, is also closed. A sign on the door says it is closed due to a power cut.
UK Power Networks, in a live update on its website, said it expects power to return between 9am and 10am.
The power outage has been caused by a fault on an underground electricity cable, the power provider said.