Vicky Candlin reports for Newsroom SouthEast

The A406 North Circular Road between Harrow Road and the Hanger Lane gyratory system is standing in water up to 25ft deep in some places and will not reopen until the end of this week at the earliest.

The Metropolitan police have advised drivers to avoid the area and to leave extra time for their journeys.

'One of the biggest'

Local diversions are in operation via Bridgewater Road, Wembley High Road and Harrow Road.

BBC traffic services reported severe conjestion on other areas of the A406 North Circular, with traffic crawling westbound from Staples Corner, M1 junction 1.

Engineers from Thames Water have now isolated the damaged section of pipe after it gave out on Saturday evening.

They are currently working with emergency services to pump the equivalent of a small lake away from the road into the nearby River Brent.

'Fact of life'

A spokesman for Thames Water said that the burst was "one of the biggest we've ever had to deal with".

"Unfortunately such burst are a fact of life," he said.

"There could have been a number of contributing factors, including traffic movement, temperature fluctuations and changes in water pressure.

"Obviously once we have pumped the water away we will have to clear up the mud and filth and resurface the road, after assessing the damage.

"We do apologise to anyone affected by the burst for any inconvenience they might have suffered."