The EMA has been particularly good at getting boys to stay on at school
Six out of 10 of England's poorer students would drop out without their college allowances, a poll for the National Union of Students suggests.
A survey of 1,205 education maintenance allowance (EMA) recipients in England's schools and colleges suggests 61% would not be able to continue without it.
This figure rose to 65% among learners on the maximum grant of £30 a week.
The survey comes as about 90,000 students wait for grants to be processed amid administrative delays.
'Lack of support'
The NUS poll was commissioned and carried out before the present problems, which at one point saw up to 162,000 applicants caught up in a processing backlog.
EMA was introduced in 2004 to encourage poorer students to stay in school or college.
Those who qualify get between £10 and £30 a week, depending on their parents' income.
In the poll, recipients were asked what the grant meant to them and how easy it was to obtain, among other things.
Its key findings suggest that the allowance, is a vital source of day-to-day support for hundreds of thousands of students in further education.
The majority could no longer continue studying and would be forced drop out without EMA, it adds.
But it also highlighted problems with the application process, with a third saying they found it difficult.
This was partly because of the bureaucratic nature of the form and partly because applicants lacked family support.
And the survey also suggested the amounts being awarded were not sufficient to cover the essential costs of the poorest learners.
NUS vice president for further education Beth Walker said the current delays to processing EMA applications were totally unacceptable
She added: "There must be a full investigation into why many thousands of learners have been failed and to ensure that this situation can never occur again."
The NUS also recommended that the EMA income assessment take account of how many learners or dependent children there are in one family.
A report based on the survey findings also called for general improvements to be made to the administration of the scheme.
The government should ensure the rates rise in line with inflation and that those living in London and the south-east of England should get a higher rate.
The report said: "Particularly in the light of the disastrous introduction of the new EMA processing system in 2008, the LSC and the government have an opportunity to rebuild confidence in EMAs by improving the system on the basis of our recommendations."
Ms Walker continued: "Every year, students have to struggle through unwieldy levels of bureaucracy to obtain the EMA.
"This report shows the challenges they face, while reminding anyone who was in any doubt of how important this form of student support is to keeping young people in education."
Learning and Skills Council chief executive Mark Haysom said he agreed that the EMA was vital to young people from less well-off families in education.
"The LSC is strongly committed to helping eligible young learners benefit from EMA, and to make sure that the administration of EMA goes as smoothly as possible.
"I very much regret that there has been a delay in the processing of some EMA applications this year, but the backlog is now reducing steadily."