M25 shut between junctions 8 and 10 after crash
Lanes two, three and four of the anti-clockwise carriageway need to be resurfaced due to a diesel spill, while lanes three and four of the clockwise carriageway will shut to allow the central reservation to be replaced.
At about 09:45 GMT, National Highways said a resurfacing operation was under way and the closure was expected to remain in place until at least 15:00.
Traffic is being diverted onto the A240 and the A217.
National Highways said a lorry had "struck the central reservation and come to rest sideways across the carriageway".
The vehicle had since been removed.
Surrey Police said it hoped to have the anti-clockwise carriageway fully reopened by Monday evening's rush hour.