The TES poll found that 9 per cent of those in the capital would object to the searches, compared to 4 cent of those in other areas.
However, London parents also believed in tougher punishment for children who threatened or assaulted teachers or who carried knives in school, with significantly more saying such pupils deserved permanent exclusion.
Parents in the capital seemed significantly less impressed than others by teachers' ability. One in 10, twice as many as elsewhere, said the main problem in schools was "poor teaching standards".
Tim Brighouse, the London schools' commissioner, said parents' views of the capital should be compared to those living in other cities rather than the whole of the rest of England.
"You would expect parents in urban areas to be more critical because they have sharper choices to make when they pick schools and there can be less stability with staffing," he said.