Figures obtained by Times Higher Education under the Freedom of Information Act reveal the intense competition for short-term, early-career jobs, which are often viewed as a stepping stone to a full-time academic post.
A total of 611 people applied for two junior research fellowships in arts subjects at Clare College, Cambridge in 2010-11. Another 173 submitted research proposals for a single science post.
Nearby Christ's College received 461 applications for two posts in the arts, humanities or sciences - up from 328 in 2009-10.
With so many young academics chasing a handful of places, the sector risked creating "a disillusioned generation" of academics that would migrate to other sectors, warned Linda Evans, a reader in education at the University of Leeds who has studied early-career development.
"I can't recall a time when it's been so difficult to secure a post - we have the largest numbers of aspiring academics chasing a scarcity of jobs," she said.
"It must be so disheartening for early-career researchers who put in application after application only to keep getting knocked back.
"In my field, it's recognised that we have a problem of an ageing community of senior academics, meaning that we have a potential succession problem," Dr Evans said.
"Other subjects must have the same problem, and this means that, sadly, much talent remains untapped and is perhaps even going to waste."
Applicants to posts at Churchill College, Cambridge, had only a 1 per cent chance of success after nearly 500 people applied for five junior research fellowships last year.
Cambridge's largest college, Trinity, offered eight posts in 2010-11 and received 233 applications.
At University College London last year, research associate posts attracted an average of approximately 17 candidates as 8,474 individuals applied for 510 jobs.
Meanwhile, there were nearly 10 bids for every early-career fellowship offered by the charitable Leverhulme Trust, with 717 applications for 74 positions.
With competition so fierce, there are often complaints that internal candidates are accepted ahead of more qualified external applicants, who lack a champion on the interviewing panel.
Gillian Evans, emeritus professor of history of medieval theology and intellectual history at Cambridge, said: "Obviously there will be the odd bit of patronage, but when candidates are interviewed there will be others on the panel and special pleading can't necessarily fix anything."
Those lucky enough to land a post frequently found that they were short-term appointments, which was a growing trend, Dr Evans added.
"Early-career researchers find themselves moving from temporary post to temporary post, constantly looking out for the next vacancy.
"This isn't good for anyone. Researchers often leave the team before a project is finished, resulting in lack of continuity and duplication of effort when a replacement has to be trained and brought up to speed.
"And insecurity leads the researcher to focus her or his efforts on securing the next post rather than on career development."