The M25 will be shut overnight next week to allow "urgent repairs" to take place.
The Department for Transport authorised the urgent repairs because there was a "likelihood of danger to the public and of serious damage to the road."
The M25 will be closed overnight on May 27 between Junction 21a and Junction 20.
The final section of the emergency works will be completed on June 2, with the Highways Agency carrying out work on the M25, Junction 21a slip road.
Diversions will be in place and motorists are being by authorities that delays are likely.