The M25 clockwise is closed resulting in severe delays, due to a van fire near to junction 5 for Westerham .
The van is blocking a carriageway and firefighters were called out to put out the blaze, no one was injured. Work to recover the van is underway.
The incident has caused miles of congestion. One of the lanes was already closed for roadworks. Trapped traffic is being escorted via a rearward relief.
The closure has prompted further delays between West Wickham and Badgers Mount on the A21 as traffic diverts.
The M26 westbound has also been closed because of the fire, with diverting traffic affecting areas in Seveneoaks, Sundridge and Westerham.
A spokesman for Kent Police said: "Kent Police was called at 3.41pm to reports of a van on fire on the M25, just prior to Clacketts Lane Services. Emergency services are on the scene."
A Kent Fire and Rescue Service spokesman added: "We were called to reports of a van alight on the M25 near to junction 5 for Westerham, on the clockwise carriageway.
"Two fire engines were sent to the scene and crews wearing breathing apparatus used hose reel jets to extinguish the blaze. The cause is not yet known."