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There may be some minor congestion towards Reading services, but the clear up work has finished.
At 12:20 GMT we spoke to Ian Jobson from Highways England, who updated us on their progress clearing the HGV and contents.
Duty Manager for Highways England South East, Ian Jobson, said:
M4 Berkshire eastbound severe disruption, at J12 for A4.
M4 Berkshire - M4 entry slip road closed London-bound at J12, A4 (Theale).
Check local traffic and travel reports for:
The M4 in Berkshire is currently closed eastbound between J13 and J11 due to an overturned lorry and subsequent spillage.
There is a signed diversion route in place and eastbound traffic should follow the Hollow Circle diversion symbol via the below route:
Exit the M4 at J13 and taking the 3rd exit, join the A34 southbound.
Two lanes are closed on the M4 London-bound after a lorry overturned on the carriageway, spilling bleach and diesel on the road.
There is currently heavy congestion between junctions 12 (Theale) and 11 (Reading).
The lorry is now on its wheels but recovery is ongoing, meaning the M4 remains closed.
Lanes are expected to re-open as late as 4pm this afternoon.