According to the report, graduates are more likely to be employed in non-graduate jobs than they were 10 years ago, when the figure stood at around a quarter.
The number of unemployed graduates has also risen, with nearly a fifth of people with degrees finding themselves out of work at the end of 2011.
Trades Union Congress (TUC) General Secretary Brendan Barber called for an industry strategy to reverse the trend of graduates taking jobs that did not require a degree.
Mr. Barber said that a lack of quality jobs was to blame for the growing trend, and that the government should focus their efforts on boosting high quality industries like manufacturing.
He warned that without intervention from the government, “”Public investment in education and talents of graduates will continue to be wasted.”
Of those graduates who are employed, those with degrees in medicine and dentistry are the best paid, with an average salary of just over £21 an hour.
At the other end of the scale are graduates with arts and humanities degrees, who earn an average of just £12 an hour.
However, the study reveals that this is figure is still well above the hourly wage for adults aged 18 to 64 without degrees – whose average stands at just under £9.
The report also suggests that those with degrees are less likely to be unemployed than the rest of the available workforce, with 86% of graduates employed at the end of 2011 compared with 72.3% of non-graduates.
Finally, unemployment figures for recent graduates have fallen 1.6% since the peak of the recession when they stood at 20.5%, suggesting that employment prospects for graduates may slowly be improving.
Commenting on the report, Carl Gilleard of the Association of Graduate Recruiters says that it proves that degrees are still a worthwhile investment of time and money.
"My advice for graduates is to have both a short term and long term approach to planning their careers, to gain experience in the workplace and see it as a valuable a stepping stone towards their longer term career goals."