One in four aspiring solicitors has done unpaid work experience for more than six months at a time, according to a new survey by the Law Society's Junior Lawyers Division.
JLD chair Sophia Dirir said there was a worrying trend of long-term unpaid work experience, with some placements lasting up to two years.
'I would urge the profession to re-evaluate the situation and not push short-term commercial advantage above the development of future legal talent,' she warned.
More than 600 young lawyers responded to the JLD's 'Early career work experience survey'.
The number of people undertaking paralegal work straight after study jumped from 45% in 2013 to 60% this year. Of the 60%, just over half made the jump from paralegal work to training contract.
Meanwhile, figures suggest smaller firms struggle to retain young lawyers. Just over a quarter of respondents (27%) who had not undertaken paid work experience were interested in joining a smaller practice. As the age of respondents increased, they were more likely to seek work in a high street practice than in a medium-sized or magic circle firm. Respondents over the age of 35 were more likely to work in-house.
Other findings include:
Elsewhere, legal aid work was not popular, with just 4% working or interested in the field.
Law Society Andrew Caplen said: 'Legal aid cuts and wider funding cuts are chipping away at access to justice. This latest research paints a grim picture of the future of legal aid, with fewer lawyers entering this essential area of law.'
He added: 'Students thinking of embarking on a career in law should think carefully and do extensive research. Students should be confident that they are right for the profession and the profession is right for them before making that commitment.'