Tom Kelly, former chief executive of Colleges Scotland, said the Scottish Government's Post-16 Education (Scotland) Bill would extend the patronage of ministers and conceal reductions in funding.
The SNP's approach also came under fire from the former Scottish Executive Deputy Minister for Lifelong Learning Allan Wilson, who said the reforms were not supported by any educational rationale.
Michael Russell, the Education Secretary, believes the programme of college regionalisation will deliver savings of £50 million annually, improve governance and ensure courses are better aligned to employers' needs.
However, writing in the newsletter of the Edinburgh-based Invicta Public Affairs agency, Mr Kelly questioned the benefits of the policy.
He wrote: "The SNP Government should set out honestly its case for both centralising control and for drastic cuts in funding for colleges.
"Instead, it uses a smoke screen of fictional necessities, structural upheaval and bogus figures to suggest reform in the interests of greater efficiency and benefit to students."