Is the M4 shut?: Greater London motorway closed between Cranford and Brentford after serious crash, when will it reopen

National Highways said the carriageway remains closed eastbound between Junction 3 (Cranford) and Junction 2 (Brentford) due to the incident, causing “very long delays both ways”.

In a statement, National Highways said: "The M4 in Greater London is closed eastbound between J3 (Cranford) and J2 (Brentford) due to a serious collision. All emergency services including the Metropolitan Police are in attendance. National Highways Traffic Officers are also on scene providing assistance with traffic management."

As a result of the incident, lane 2 on the westbound carriageway is also closed to allow emergency services access to the scene. "Lane 2 (of 2) is also closed on the westbound carriageway to allow for emergency service access to the scene," National Highways confirmed.

Drivers heading towards London are being advised to seek alternative routes. "Traffic heading for London is advised to use the A40 eastbound," the statement said.

A diversion route is in place, with traffic being directed via local routes around the closure. Normal traffic conditions are expected to return at 5pm.