Images posted on social media show some of the vans have been daubed with graffiti, had their cameras covered by bags and their tyres deflated.
One was photographed being rescued by a recovery truck.
More than 4,000 people have joined a Facebook group encouraging people to report sightings of the vans.
The vehicles are being deployed as many fixed Ulez cameras have been put out of use by opponents of the Ultra Low Emission Zone which was expanded to Outer London last month.
Asked about the attacks on the vans, Croydon South MP Mr Philp told LBC Radio: “I condemn it.
“I obviously can’t support and condemn criminal damage and violence of any kind.
“No-one should be doing that.”
He added: “Obviously, I completely oppose Ulez. It’s a terrible imposition on my constituents, Outer Londoners, by Sadiq Khan.
“It’s a greedy, money-grab, punshing people on lower incomes.”
Health experts say Ulez will boost to some degree the battle against toxic air in London, which is stunting the lung growth of some children, and causing other health harms.
But Mr Khan has been accused of rushing in the expansion of the scheme to the whole of the capital and giving drivers of polluting vehicles little time to change them.
Ulez cameras use automatic number plate recognition (ANPR) technology to identify vehicles.
People who drive in the zone with a non-compliant vehicle and fail to pay the £12.50 daily fee are initially being sent warning letters.
In the coming weeks TfL is expected to begin issuing £180 fines, reduced to £90 if paid within 14 days.
A Transport for London (TfL) spokesman said: “Vandalism is unacceptable and all incidents on our network are reported to the police for investigation.
“Criminal damage to Ulez cameras or vehicles puts the perpetrators at risk of prosecution and injury, while simultaneously risking the safety of the public.
“Camera vandalism will not stop the Ulez operating London-wide.
“All vandalised cameras are repaired or replaced as soon as possible.
“We have an extensive camera network which is sufficient to support the effective operation of the scheme.
“Anyone driving a non-compliant vehicle within the expanded zone will be detected and we advise everyone to check whether their vehicle is compliant and to consider the various support that is available to help transition to greener modes of transport.”
There were 510 crimes relating to Ulez cameras reported between the start of April and the end of August, figures released by the Metropolitan Police show.
Two arrests have been made, with one person charged and bailed and the other case discontinued by the Crown Prosecution Service.
Mayor of London Sadiq Khan previously warned people attacking cameras that “protest should be lawful, safe and peaceful”, adding: “It is really important to stay on the right side of the law.”