Students at Sheffield Hallam University are planning to withhold tuition fees in an attempt to force a government U-turn on the issue.
Reading University student union is also taking legal advice over whether to withhold fees in an action it stresses would be against the government rather than the institution.
Charlotte Matthews, Hallam student union president, said: "The fight isn't aimed at universities but this is the best way to campaign against the fees."
A spokesman for the National Union of Students said student unions would jeopardise their charitable status by running non-payment campaigns and was not encouraging them.