The spending watchdog published a report yesterday (1 February) claiming that more than two-thirds of apprenticeships created in England in the past five years were taken by the over-25s.
It added that just one in five of those running in 2010/11 lasted less than six months.
Unite assistant general secretary Tony Burke, said: "This report shows the real value of offering adults the opportunity to start an apprenticeship.
"With the ongoing skills gaps and shortages in the UK manufacturing sector, it is only through apprenticeships that the UK can produce the 'home grown' talent to produce the highly skilled workers of the future."
The report also noted that the number of apprenticeships doubled between 2006 and 2011, with a total of 443,000 apprenticeships starting during that time, of which 300,000 were adult apprenticeships (19 or over).
Completion rate increased from 47% to 75% during that time, while over-25s accounted for 68% of the increase in new apprenticeships.