This is the first time for many years that applications for Cambridge have fallen so dramatically, while the increase at Oxford was dampened by a downturn in the proportion of applications from state-school pupils.
Cambridge was unable to comment at this stage on the percentage of state and private-school applicants.
"We have not done an analysis of where this drop is," said Susan Stobbs, director of admissions for the Cambridge colleges. "We are waiting for the proper data base with all the details."
Over the past 12 years the number of overall applications at Cambridge has risen by 40 per cent, making this year's steep drop all the more inexplicable.
"It is too soon to see whether this is a national trend, because other universities will not have their numbers until December," said Ms Stobbs. "We have a veterinary school and there are changesin the application process to that. We were expecting a reduction."
The University and Colleges Application Service refused to be drawn into the speculative fray: "We are not anticipating a drop in applications. You really can't tell how it is going to go."
Meanwhile, Oxford remains sanguine about the decline in state-school applicants, 54 per cent down from 56 per cent last year, insisting that postal delays due to floods and sickness at the Oxford postal depot, are still seeing applications trickling in.
As for the Laura Spence effect, a spokesman for the university thinks the rejection of the high-flying comprehensive pupil probably did the university a favour: "I don't think it did us any harm", he said. "Any news coverage is good coverage".
The damage may also have been limited by initiatives such as the Oxford access scheme, which targets ethnic-minority pupils from inner-city schools. The latest figures show that one quarter of those on the scheme were offered places, in contrast to the one in five applicants who usually succeed.