Liam McArthur, the party's education spokesman, made the claim after a meeting of Holyrood's Education committee to discuss Scottish Government reforms to universities and colleges. He said legislation which backs greater recruitment of students from poorer backgrounds would "displace" other socio-economic groups.
It came as Alan Simpson, who leads the body that represents the chairs of university Courts, said the same legislation would pave the way for the greatest political influence over higher education for more than a century. The Post-16 Education (Scotland) Bill gives ministers powers to set priorities for universities in return for public funding.
Mr McArthur said: "What we have heard confirms the fear that many Scots-domiciled students who currently have such opportunities will lose out in future."
A spokesman for Education Secretary Michael Russell said Mr McArthur was wrong, adding: "Our universities work best for Scotland when access is based on ability to learn, not the ability to pay."