Jersey's Chamber of Commerce says proposals to introduce a new tax on larger retailers lacks detail.
Senator Sarah Ferguson wants those making more than £500,000 in profit to be taxed at a rate of 20% - in an effort to cut down on UK chains sending their takings off-island.
Her amendment to the 2017 budget will be debated next week.
The Treasury Minister backs the concept of corporation tax being extended beyond the existing limited number of firms - primarily in the finance sector - which currently pay it.
The Chamber of Commerce says the move appear to be a positive step in terms of creating a level tax playing field, it thinks there is insufficient information in what's being proposed.
It specifically wants to know why only retailers would be targeted and whether the risk of companies facing double taxation, that's a tax bill in two different jurisdictions, has been investigated.