Just Stop Oil protesters have climbed onto a major bridge that links Essex and Kent, causing five miles of queues during rush hour and affecting the M25.
Essex Police said the 275ft Queen Elizabeth II Bridge at the Dartford Crossing is closed to traffic after the report was made shortly before 3.50am this morning.
The climate change protest group, currently staging a month of disruptive protests across the capital and surrounding areas, has claimed responsibility for the stunt.
"At approximately 5am, two climbers ascended the two 84m masts on the North side of the Queen Elizabeth II Bridge, demanding an end to new oil and gas," Just Stop Oil said in a tweet.
The bridge has been closed by police with drivers currently being diverted through the tunnel.
The A282 Dartford Crossing is currently the only way to cross the Thames east of London by road.
Just Stop Oil say that two climbers ascended the two 275ft masts on the north side of the Queen Elizabeth II Bridge at 5am this morning.
They say they expect that the bridge will remain shut for at least 24 hours.
One of the protesters, Morgan Trowland, 39, a bridge design engineer from London, said: “As a professional civil engineer, each year as I renew my registration, I commit to acting within our code of ethics, which requires me to safeguard human life and welfare and the environment.
"Our government has enacted suicidal laws to accelerate oil production: killing human life and destroying our environment. I can’t challenge this madness in my desk job, designing bridges, so I’m taking direct action, occupying the QE2 bridge until the government stops all new oil.”
Another protestor, identified only as 33-year-old Marcus, a teacher from London, added: “Too many people in this country simply don’t know the scale and intensity of climate breakdown as the scientists describe it.
"The authorities are criminally failing to get this grim science communicated. During Covid the science was conveyed on a daily basis. Why isn’t the most existential threat that humanity has ever faced on the news every day?
“Our political system is betraying the people of this country. More fossil fuel licenses means global genocide. Only direct action will now help to reach the social tipping point we so urgently need.”
The 2.8km-long (1.7 mile) QEII bridge southbound, and two 1.4km-long (0.8 mile) tunnels northbound link Essex and Kent.
The A282 also connects directly at both ends with the M25 London Orbital Motorway, one of the busiest motorways in Europe.
National Highways has warned drivers that there are currently two hour delays and five miles of congestion.
A spokesperson from Essex Police said: "Officers are currently working to resolve a situation which has caused us to close the QEII Bridge at the Dartford Crossing.
"We received a report shortly before 3.50am today (Monday 17 October) that two people had climbed onto the bridge and are currently at height.
"The bridge has been closed while we resolve the incident which we will do as quickly and as safely for all involved.
"It does mean that we have had to close the bridge to traffic, but a diversion is going to be put in place through the tunnel.
"This is likely to cause delays throughout this morning and this incident may take some time to resolve due to the complexities of safely getting people down from height.
"Please plan your journey."
The force added: "We will take action against anyone who puts life in danger or things they can selfishly stop others getting to work or getting on with their lives."
