The students, who come from universities across Scotland, are petitioning the Law Society of Scotland, arguing that the current arrangements discriminate against students from deprived backgrounds.
The Campaign for Fair Access to the Legal Profession wants studying to become a solicitor to be given equal status with a medical degree to ensure students get full financial support for the duration of their study period.
Currently, students who complete a four-year law degree get lower levels of financial help when they go on to complete their training with a post-graduate diploma – adding as much as £10,000 to any existing debts.
An alternative solution would be for students to work during the latter period of their training to ensure debt does not put off those from poorer backgrounds.
In January, The Herald revealed that fewer than one in 12 entrants to law degree courses at Scottish universities come from deprived backgrounds, raising fears the profession is still a middle-class preserve.
Tim Haddow, a spokesman for the campaign – which is also backed by the Scottish Young Lawyers Association – blamed inaction by successive governments for creating a new "crisis of access".
"It threatens to set social diversity in the legal profession back 50 years and leave those from less privileged backgrounds unable to convert a law degree into a legal career," he said.
"As with other professions, such as medicine or dentistry, aspiring lawyers study for five years, but unlike medicine and dentistry, legal education is split into a four-year law degree and a one-year Diploma in Professional Legal Practice. Doctors and dentists, vets, teachers and architects receive five, and sometimes six, years of student loans for living costs, but aspiring lawyers are not eligible for assistance with their fifth year.
"We have asked the Government to allow diploma students access to the same means-tested loans available for the first four years of study. Failing that, we need a radical restructuring of legal training."
Robin Parker, president of NUS Scotland, echoed the concerns, and said: "The statistics speak for themselves and we clearly need to do much more to improve Scotland's poor record on fair access, at all levels."
However, a Scottish Government spokesman said ministers were working with universities to ensure access to higher education was widened to more students from less well-off backgrounds.
"With particular regard to postgraduates and the legal diploma, in 2011 the Scottish Government changed the level of support available to ensure that an extra 2300 students every year are eligible for loan support of up to £3400 towards the cost of their tuition fees.," he said.
The Campaign for Fair Access to the Legal Profession was set up last year after concerns about equity of access to law courses following Government funding changes.
Fiona McAllister, president of the Scottish Young Lawyers Association, said: "The changes to the funding arrangements mean diploma students having to self-fund, rely on family assistance, or turn to a bank for a loan. The issues surrounding funding for the diploma and its ramifications for young lawyers have been of long-standing concern for the SYLA."