The incident between two vehicles happened on the A227 near Wrotham just before 11.20am today (August 18).
A tractor subsequently fell onto the central reservation between junction two and three of the M20.
M20 London Road Wrotham crash: Live traffic updates
Kent Police is currently attending the scene alongside Kent Fire and Rescue Service and South East Coast Ambulance Service, where one man has been airlifted to hospital with serious injuries.
Both the M20 and the A227 at the scenes remain closed while emergency services attend the incident.
Motorists are advised to use alternative routes where possible.
This is a breaking news story. More to follow.
