Drivers continue to face long delays on a key motorway after a serious collision involving multiple vehicles in Buckinghamshire.

The M40 northbound in Buckinghamshire is closed between J1a Denham Interchange (Watford (M1), Rickmansworth, Heathrow Airport, Slough (M4),(M11, M23) M25) and J2 Beaconsfield Interchange (Beaconsfield, Amersham, Slough A355; Beaconsfield Services).

National Highways reports that a serious collision occurred on the approach to Junction 2 and involved several vehicles.

The accident prompted Thames Valley Police, Buckinghamshire Fire and Rescue, South Central Ambulance Service and National Highways to send teams to the scene.

Large parts of the M40 remain closed this morning

Traffic maps from National Highways show long delays along the M40, with closed roads, while stationary traffic can be seen to the east of the J1a entry slip.

The incident was first reported at around 1.30am this morning, with National Highways: East providing updates on the situation via social media.

At 5.30am, the transport organisation reported that the road is expected to remain closed until at least 8am, although they warned it could be longer.

Drivers are dealing with long delays along the M40

In the most recent update, it said: "The #M40 northbound between J1a (#M25) to J2 (#Beaconsfield) remains CLOSED for a police investigation following a multi-vehicle collision.

"The road is expected to be closed for several further hours."

The road issue could cause havoc for motorists attempting to access London Heathrow Airport, especially as Britons look to make use of the warm weather.

National Highways stated that motorists should allow for extra journey time if the closure impacts their planned route.

Drivers are being advised to plan ahead and potentially even "re-route or even delay your journey".

National Highways has outlined a diversion route for motorists to follow after the multi-vehicle collision.

National Highways said they expected the M40 to remain closed for several hours