The M4 is blocked in South Gloucestershire following a vehicle fire and oil spillage.
Highways England said the M4 westbound was closed at around 8.30pm from Junction 18 (Tormarton) to 19 (Hambrook) due to a spillage on Lane One following a vehicle fire.
"The oil spillage is over 250 metres," Highways England tweeted. "Please take care on approach.
"Contractors are now on scene clearing up the oil spillage from the earlier vehicle fire."
UPDATE: The incident has now been cleared.
The delays come after Bristol was due to be hit by disruption to a Brexit protest which never materialised.
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Brexiteers said they would drive slowly and form a blockade at rush hour, moving along the M5 southbound to Clevedon and then along the M4 to Bath.
Yet there was no disruption to Bristol traffic and only a small amount in Devon, Cornwall and Exeter.
As 10 vehicles moved off from Cornwall at 3.30pm to kick off the protest, organiser Ian Grindod said: “It was never going to be a massive event anyway."
