Drivers are being warned of long delays after emergency repairs on the Dartford Crossing.
The right-hand tunnel has been shut, reducing capacity by half.
The work is causing hold-ups on the M25 anti-clockwise between J31 A1306 (Lakeside/Purfleet) to J1A A206 (Dartford).
The left-hand tunnel remains open.
National Highways is also reporting of delays of around an hour on the M25 anti-clockwise due to a collision at J30 for Thurrock.
