UPDATE: While many users had their power restored, some pockets in IP9 1, remained affected and at 9am UKPN put out this message on its website:

Reason for this unplanned power cut

We're investigating a high voltage overhead electricity line fault which has caused a power cut in the local area.

Earlier today -

Hundreds of Shotley residents experienced a power cut this morning.

UK Power Network quickly re-established supply to Shotley Gate by 6.45am, after a 40 minute break.

The power company sent out messages explaining they were working on the issue.