The Forum of Private Business (FPB) fears that SMEs may be pushed off the government's agenda following the recent cabinet reshuffle.
Matthew Goodman, the FPB's policy representative, said: "Stephen Timms' departure has put the government's progress on the Enterprise Framework in jeopardy.
"The danger is that, with this shift in personnel, the small-business agenda may be pushed further towards the margins at a time when it desperately needs to be centre stage."
Mr Goodman also feels that the FPB is marginalised by the government when compared to the treatment that the Business Council for Britain - which represents larger firms - receives at the hands of the country's leaders.
The FPB has also been critical of government statistics surrounding SMEs.
In January, the government said that there were more SMEs in the UK than ever before, with 180,000 being created each year.
However, the FPB disputed these claims and said that many firms were struggling due to increased red tape and taxation.
