The exit slip road - as well as lanes one, two and three - has also been closed.

The road surface in lane two is said to have 'collapsed' at around 5.30am this morning.

Tailbacks are all the way back to Heathrow and seriously affected West London as anti-clockwise travelling vehicles seek rat runs.

Surrey Roads Police, who have been at the scene since around 6am, said more than 25 vehicles had suffered punctures as a result of the puncture.

Tweeting this morning, they said: "#M25 jct 9 to 8 road surface has failed. Large number of vehicles have damaged tyres."

There are severe delays on the motorway, with traffic stretching back to junction 13 (Staines).

Travel time is forecast to be around 120 minutes.

More as we get it