Crews have attended a crash on the A12 (Image: ©Archant Photographic 2010)
The M25 has been closed between the slip roads for J27 because of a multi-vehicle crash.
Tailbacks are backing up as far as junction 25 while emergency services attend the incident, which happened at around 12.30pm.
The accident involved a car, two lorries and a motorbike.
On motorcyclist has been taken to hospital with serious injuries.
The Highways Agency, who are leading on the incident, say the road will reopen as soon as it is safe to do so.
There are currently delays of around 60 minutes with traffic being diverted onto the M11.
Police are advising drivers not to use the M25 clockwise through Essex.
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