Drivers who ignore diversion signs during this weekend's M25 closure could be liable for the £12.50 Ulez fee.

Motorists looking to find quicker alternative routes on minor roads could end up in London’s ultra low emission zone (Ulez) if they move off the official diversion routes set out by National Highways.

The daily Ulez fee will apply if their vehicle doesn't meet minimum emission standards.

Failing to pay the charge could result in a £180 fine, reduced to £90 if paid within 14 days.

The M25, which will be closed in both directions between Junctions 9 and 10 in Surrey from 9pm on Friday, May 10 until 6am on Monday, May 13, is being closed to facilitate the lifting into place of concrete beams for a new bridge and gantry.

Motorists are strongly encouraged to avoid the area altogether if possible.

The diversion routes in place will guide cars on a 19-mile detour on A roads that cross from Surrey into London’s Ulez area.

News Shopper: This is the second of five M25 weekend closures in the busy junction 10 areaThis is the second of five M25 weekend closures in the busy junction 10 area (Image: Yui Mok/PA Wire)

National Highways senior project manager Jonathan Wade said: "Although the (Ulez) cameras will be active, no enforcement action will be taken.

"However, if you ignore the diversion signs and do your own thing, then if your vehicle’s not compliant you do run the risk of getting caught.

"You’ll be perfectly safe as long as you follow the diversion routes."

Concerns have been raised that sat navs could unintentionally lead some drivers onto minor roads after leaving the M25, potentially exposing them to Ulez cameras and creating gridlock in residentional areas.

London's Mayor Sadiq Khan expanded Ulez to cover the whole of London on August 29 of last year.

This weekend's closure will be the second of five planned M25 closures on sections connecting with Junction 10, part of a £317 million improvement project.

READ MORE: M25 set for second full weekend closure at junctions 9 and 10

The first planned closure between Junctions 10 and 11 in March saw traffic levels that were more than two-thirds lower than normal, thanks to an extensive awareness campaign.

Mr Wade expressed concerns that the lack of disruption then might cause some drivers to disregard precautions this time.

He said: "We’ve upped the amount of correspondence that we’ve been sending out to try and counter that but it remains an issue."

Some parts of the M25 will also experience disruptions this weekend due to scheduled retrofitting work of additional emergency stopping areas on smart motorway sections.

Mr Wade also assured that the Junction 10 work could be stopped at various points throughout the weekend if it runs behind schedule, stating "we wouldn’t jeopardise opening the M25 on Monday morning".

RAC spokesperson, Alice Simpson, highlighted that drivers might face "up to six days of disrupted travel" as the M25 closure follows national rail strikes expected to increase traffic levels.

She encouraged drivers to plan ahead, and added: "Rather than relying on a sat nav, check the planned diversion routes ahead of time and be prepared for long delays.

"It’s also a really good idea to check your vehicle’s oil and coolant levels, tyre pressure and tread depth all before setting off to reduce the chances of a very unwelcome breakdown."

There will be three more closures of the M25 between August and the end of the year.

The current project, set for completion in summer 2025, aims to increase the number of lanes and improve access to the M25 at Junction 10, one of the UK’s busiest and most dangerous motorway junctions.