UPDATE 10.20AM: All lanes have been reopened on the M4 eastbound between junctions 16 and 15 after this morning's crash.

Delays of up to 20 minutes remain in the area.

Two lanes of the motorway were initially shut following the accident.

Queues built up as the emergency services deal with the road traffic  collision, which happened at 8.40am.

UPDATE, 9.30AM: Traffic has been fully stopped to facilitate recovery.

Delays of at least 50 minutes remain on the approach. Highways England is advising motorists to allow extra journey time.

UPDATE 10AM: Vehicles have now been recovered to the hard shoulder and traffic released. Lanes two and three were reopened at 9.40am. Delays are expected to ease, but travel time is still around 35 minutes and queues are reported to be up to six miles long.