The man, in orange overalls, is seen in video postsed by the protest group approaching activists on Blackfriars Bridge. He grabs the first protesters he sees hurling him onto the pavement where the victim rolls into a police officer.
The officer looks up and with a colleague tackles the irate worker.
In the footage he is pushed up against a waste management truck by police with another furious driver barking at officers: “You shut up, get off my truck”.
Police shout at the suspect to “put your arms behind your back” as they detain him on suspicion of common assault.
During the struggle, the officer says: “You are f***ing assaulting people”.
Another passer-by tells the officers to “give the guy a break, he’s just trying to get to work”.
He was not arrested, the force later said.
Just Stop Oil said in a statement: “Tensions have been high this morning as the marches cause major delays for commuters.
“One man threw a supporter onto the ground and was subsequently arrested on Blackfriars Bridge.
“A motorcyclist attempted to drive through the same procession, before police intervened.
“Elsewhere there were a number of altercations as members of the public snatched banners and confronted Just Stop Oil supporters.”
One of the activists on the slow march Barry Farrent, 66, said: “Society needs to wake up to the ongoing destruction of our home.
“These criminal politicians have us on the highway to climate hell with their foot on the accelerator. The UK has a proud history of civil resistance and bringing about world-wide change.”
Scotland Yard said: “At around 8.25am officers detained a male member of the public for common assault after an altercation between him and two Just Stop Oil protesters on Blackfriars Bridge this morning.
“There have been no arrests.
“Police are investigating the matter.”
It came amid large-scale protests on Tuesday morning with 45 activists slow-marching across London, Tower and Blackfriars Bridges.
Tensions boiled over again on Friday as a man got out of his car and threw a female activist to the ground in Mansell Street - a stone’s throw from the Tower of London.
The woman picks herself up and goes to sit on the pavement as the motorist continues to square up to others.