The baffling footage is the latest protest against the vans, which use number plate recognition cameras to catch and fine non-compliant vehicles driving in the ULEZ.
Activists opposed to Mr Khan’s flagship policy – which last month expanded to cover the entire city – have already attacked hundreds of static cameras prompting the London Mayor to roll out a fleet of vehicles to catch those flouting the rules.
But these too have become a target, with opponents to the Ulez – who call themselves ‘Blade Runners’ – slashing their tyres, spray painting cameras and smashing windows.
However, some activists have taken to protesting in a more ‘peaceful’ method by simply using other vehicles to block the camera’s view, forcing vans to move on.
Footage seen by MailOnline, has shown the moment one group used a tipper truck with ‘ULEZ Camera’ to block the van in London.
Activists, one dressed as a dinosaur and another wearing a dog costume, then mock ULEZ officials, who are speaking to two officers from the Metropolitan Police.
‘You’ve got us for company and we’re very nice, we keep you company, don’t we,’ one ULEZ protester cheekily says to the two men in charge of the enforcement van.
The woman then turns to the pair of female police officers as they walk away from the scene, and says: ‘Peaceful protest is allowed in this country.’
‘Yes, yes,’ one officer replies before they get in their car and drive off, leaving the activists to continue with their bizarre protest.
Later, the person in the inflatable dinosaur suit is seen waddling towards to two men, as another activist holds a sign saying ‘ULEZ scam’ in front of the van’s ANPR camera.
The video comes as ‘Blade Runners’ ramped up their campaign of vandalism trashing yet another one of the vans this week.
Images show one of the vehicles with its windows and windscreen smashed, in the latest escalation by activists determined to thwart Mr Khan’s much-hated levy.
Video footage of the vandalism was shared on Facebook with the caption ‘The Bladerunners are not backing down’, with anti-Ulez activists mocking the criminal damage, hailing the vandalism as ‘amazing work’.