The Scottish Government announced the Bill this week as part of its forthcoming legislative programme and said that it would improve public awareness of lobbying of MSPs and ministers, and would take account of the findings of a recent inquiry by its Standards Committee.
The Government had promised to create a "measured and proportionate" register of lobbying.
However, a consultation has proposed criminal sanctions for offences around lobbying without registration in order to give the Bill teeth.
The Association for Scottish Public Affairs said it was "completely opposed" to criminal sanctions and said the proposal was inappropriate for a registration scheme.
ASPA said it was also concerned about the proposal that individual lobbyists should have to register rather than their employers and said the government had not clearly defined the terms ‘lobbying’ and ‘lobbyist’ for the purposes of the Bill.
Alastair Ross, convener of ASPA, told PRWeek: "A Lobbying Bill has been talked about for three years now, so we look forward to seeing the details of this legislation. It must contain a level playing field with no exemptions for different types of lobbyist, and be practical for people to use as well as being 'measured and proportionate'."