Hundreds of Wellington households are enduring their fifth day without power, and some may have to put up with the situation for several more days.

Repair crews are working round the clock to repair damage caused by last week's storm, but Wellington Electricity warns the region's electricity network is unlikely to be completely restored until next week.

A statement from the service said, as at 12.30pm today, it was aware of 500 customers still without power.

A spokesman said significant progress had been made in the worst-affected areas, including Island Bay and Lyall Bay.

However "the damage done to the electricity network is far worse than originally expected,'' he said.

"Many of the repairs needed are extensive and take a tremendous amount of technical work.''

All customers either without power or experiencing power outages must contact the emergency fault line on 0800 248 148, the spokesman said.

More than 150 extra staff have been called in from around New Zealand to help with repairs. About 30,000 homes and businesses were without electricity at the storm's peak.

- APNZ