Images reveal the scene after 80 litres of fuel and scaffolding poles are partly blocking a busy roundabout.
Drivers are facing long delays after the lorry overturned at the junction with the A12 and A130 near Howe Green yesterday at about 1.30pm.
One lane is still closed and there was queueing on all approaches of the major junction.
Fire crews, police, the Environment Agency and UK Power Networks are all on scene.
Zoe Bendall from Wickford said: "There are 2 fire engines and many police cars on scene and the recovery was just starting to attach and lift when I went past."
In an update at 3.35pm, Essex Fire Service said the overturned lorry contained scaffolding poles and 80 litres of diesel had leaked on to the carriageway.
A spokesman added: "Traffic is able to move past the scene safely but please continue to avoid the area if you can.
"Approximately 80 litres of diesel has leaked and crews are awaiting the arrival of the Environment Agency.
"UK Power Networks has been requested to make an electricity pylon safe before the lorry can be moved."
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