The northbound Dartford Tunnel has reopened after being blocked by a broken down lorry.

The fully loaded articulated HGV became stuck after its air brakes failed and remained locked on more than an hour ago.

One lane was closed leading to widespread delays on the A282 northbound between J1a of the M25 (A206, Dartford) anticlockwise carriageway in Kent and J31 in Essex (A1306, Lakeside/Purfleet).

National Highways has announced: "The broken down lorry has been recovered and all lanes are now open on the A282 northbound approach to the Dartford Tunnel. The west (left) tunnel has also been reopened."

But it warned: "Delays remain in the area but these are easing."

Earlier, National Highways had tweeted about the lorry: "It's lost air and its brakes are locked on.

"Recovery is en route. 1 lane closed. Expect delays to increase due to the time of day and traffic volume."

The west tunnel later had to be shut along with the entry slip road from J1a.

Traffic was diverted through the smaller east tunnel leading to heavy congestion at J2 of the M25 (A2, Darenth interchange).