Students responded angrily this week after advisers close to the Conservative party argued that families receiving state benefits do not deserve the further subsidy of the education maintenance allowance (EMA).
The view was expressed by Policy Exchange, the right-wing think tank, and is likely to become the basis of government policy should the Tories gain power at the next general election.
More than 500,000 students currently benefit from the Pounds 30-a-week grants, which act as an incentive for them to stay on at 16. But the carrot would no longer be needed if ministers pressed ahead with plans to raise the compulsory age of education or training to 18, says the report.
While critics of increasing the leaving age have already pointed out that such a move would endanger EMA grants, the report goes further by arguing that those from low-income families do not deserve the extra support.
The report's authors - Sam Freedman, head of Policy Exchange's education unit, and Simon Horner, a research fellow from the think tank who is now an adviser to the shadow cabinet's treasury team - said the grants should be scrapped to help fund a "pupil premium" that would provide extra cash to schools and colleges in deprived communities.
The report, titled "School Funding and Social Justice", said: "The only possible remaining argument for the EMA is social justice - that young people from poorer backgrounds deserve to be supported from 16 rather than at 18.
"This is a pretty weak argument given that the vast majority of such young people live at home - and their parents receive child benefit until they are 19 or leave full-time education."
A study by the National Union of Students and the Learning and Skills Network suggested that two-thirds of teenage FE students already support themselves with part-time jobs, and more than a third have considered dropping out because of financial pressures.
Beth Walker, vice-president of the NUS, said: "We only need to look at the distress and confusion that have resulted from recent delays in the administration of EMA to see how important this financial support is to so many students.
"The costs of further education do not disappear just because the compulsory leaving age is raised.
"We must ensure that there is adequate support available to those who would not previously have gone into further education due to the financial burden it would place on them and their families.
"It is crass and offensive for this right-wing think tank to suggest that we should cut down on the support that is available to poorer students."
David Collins, president of the Association of Colleges, said: "EMAs have made a major contribution to increasing the staying-on rate in full-time education and encouraging the participation of those who might not otherwise consider a college place. They have also had a significant effect on attendance and retention."
Leading article, page 4.