A major power failure has closed both directions of the M5 East tunnel in Sydney causing lengthy delays during peak hour.

The tunnel is closed between General Holmes Drive at Mascot and King Georges Road at Beverly Hills, causing heavy traffic as commuters try to get home from work or travel into the city for Vivid, the AFL at the SCG and to ANZ Stadium for the NRL.

Up to 100 sets of traffic lights are also blacked out in Croydon, Canterbury, Bexley, Roselands, Kingsgrove, Wolli Creek, Mascot and Burwood Heights with Network Ten saying traffic is backed up for kilometres.

Light rail services have also been affected, with no services running between Lilyfield and Dulwich Hill and a limited service running between Central and Lilyfield.

Ausgrid emergency crews are working to restore power to about 60,000 homes and businesses in Sydney’s inner west and south west that have also been affected.