In a statement the Highways Agency said: “Three lanes on the anti-clockwise M25 and the exit slip road at junction 9 remain closed as we work to investigate the cause of, and to repair a defect in the road surface.
"Safety is our top priority and we are doing all we can to reopen the lanes quickly as possible.
"In the meantime we advise drivers to avoid this section of the anti-clockwise M25 and seek alternative routes."
The AA has described the M25 as "the Road to Hell" after a problem with the road surface led to three lanes being closed near Leatherhead. Tailbacks of up to 20 miles have been reported, with the Highways Agency warning the closures could last until lunchtime. AA president Edmund King said "The M25 is critical to the nation and today's incident highlights just how dependant we are on it to funtion 24/7"
"There must be a thorough investigation into this incident. It is disappointing that not only did the road fail but it placed many drivers in danger and also reportedly damaged a number of vehicles. If this happened on the railways passengers could claim compensation. As it has happened on the roads drivers just have to put up with it"
Tailbacks caused my problems with the road surface on the M25 near Leatherhead have now reached 20 miles long, according to traffic cameras. Drivers have spent more than three hours in traffic as the anti-clockwise section near Junction 9 was reduced to one lane. Highways Agency workers are working to repair the carriageway, and confirmed there were roadworks in the area overnight. A spokesman said: "We are trying to find out from the road contractor what is going on, but at the moment we just know that there is a defect."
Due to emergency repairs on the M25 delays of up to 60 mins expected until at least 12.00pm... please leave plenty of time for your journey
There are long delays on Britain's busiest motorway amid reports that the road surface has collapsed. As the Highways Agency conducted emergency repairs in heavy rain, three lanes of the M25 anti-clockwise between junction 11 and junction nine in Surrey were closed. The agency merely described the problem as "repairs to the road infrastructure". But on Twitter people posted pictures of an uneven road surface, accompanying the pictures with words such as "collapse" and "subsidence". Surrey Police also posted pictures of a potholed M25 slip road at junction nine near Leatherhead which had to close. Huge tailbacks built up in the area with the HA advising road users to consider alternative routes and to allow extra time for their journeys.
The M25 in Surrey is still experiencing long delays between J11 and J9 due to emergency repairs to the road infrastructure, which has closed 3 lanes.
Police and Repair Specialists are currently in attendance.
The Highways Agency says road users should consider alternative routes and allow extra time for their journey.
M25 J9 closed ? been sat for 40 minutes now and not moved great start to the day http://t.co/9vLbTNhJnB
Delays are ongoing on the M25, after part of the road surface collapsed.
Surrey Police is on scene: