Millions of drivers face a summer of traffic chaos as work continues on a major M25 upgrade.

However, National Highways, the agency that has control of major roads across England, has said “peak holiday travel” plans will be disrupted by the £317 million project in Surrey.

The scheme involves restoring heathland along the stretch between junctions 9 and 10 as well as upgrading the junction with the A3 Wisley Interchange.

It says this will help reduce congestion on one of Britain’s busiest roads while improving safety and leading to more reliable journeys for drivers.

Senior Project Manager Jonathan Wade has conceded the scheme, which is due to be completed in 2025, will spell delays for road users heading to ports and airports.

Speaking to The Telegraph, he said: “The next one is scheduled for August.

“That’s still to be confirmed, but at the moment it’s been planned for August. At that time, you’re obviously into peak holiday season.”

He admitted the closures on the motorway would cause disruption no matter when they are completed.

However, he said the agency will work with airports and ports to minimise disruption for holidaymakers.

He added: “You’ve got traffic going to and from the ports of Dover and Newhaven and Folkestone plus traffic to and from Heathrow and Gatwick.

“None of these closures are planned without talking to other transport operators about the impact on them.”

August is one of the busiest times for holidays, with children in the middle of the summer holidays.

The diversion is likely to leave drivers with a 19-mile diversion.

However, it will see the number of lanes increased on what is one of Britain’s most dangerous motorway junctions. 

The stretch of the M25 will also be closed this weekend, between 9pm Friday and 6am on Monday.

It will be the second time the M25 has been fully closed during the day in 50 years.

A concrete beam will be installed for a new bridge with a gantry also put in place.

The diversion will see drivers entering London’s ULez – although National Highways says anyone sticking to the diversion route will not face enforcement, reports The Sun.