Companies are looking for answers to questions about skills shortages and access to European workers but are being met by "silence", according to a business leader.
Carolyn Fairbairn, director general of the CBI, will urge the Government to provide "clarity and certainty" over migration policy so that investment in the UK can be maintained.
In a speech in Cambridge on Friday, she will say that access to people and skills is vital to productivity.
"Let's end the game of human poker by telling EU citizens that they'll be able to stay in the UK - crucially - even in the event of a no-deal scenario.
"With record employment rates - and without access to EU workers - firms are unable to get the staff they need to grow.
"For business, this issue is as important as our future trade deal with the EU. Put simply, skills shortages threaten to slow down growth.
"Training British workers isn't enough on its own, nor is just hiring from overseas - business needs both."
Ms Fairbairn said a project to build a new factory had to be cancelled because a chicken producer could not hire enough staff.
"Problems finding the right people don't just affect the company looking for workers, they have a knock-on effect on the whole supply chain, creating a vicious cycle.
"Business is looking for answers - but is being met by silence."