European student organisations claim that a European Commission rule that has left them without European Union funding for two years is crippling their ability to serve members.
Two years ago, the commission decided that organisations such as the 17,000-member European Students Forum (AEGEE) could not receive annual grants of up to €25,000 (£16,500) unless they had a full-time employee.
Brussels wanted to ensure that EU funding was spent wisely, but the effect was to render 12 student organisations ineligible for grants on which they depended.
AEGEE president Nicola Rega said the affected groups had lobbied the commission, but had "received promises", not action.
The student groups, based in Brussels, said that under Belgium's minimum-wage system, the rule meant any EU grant could not be spent on the operating costs of the association, but only on employing a staff member.
The alternative was securing private funding, but some companies sought to influence policies, posing a "risk to our independence", Mr Rega said.