Theresa May has told MPs they have "one last chance" to deliver Brexit, as she set out a "new Brexit deal".
MPs will get a vote on whether to hold another referendum if they back the EU Withdrawal Agreement Bill, she said.
But Adam Marshall, director general of the British Chambers of Commerce, said:
"Businesses need concrete outcomes to plan for the future. In the absence of parliamentary consensus on either the withdrawal agreement or any other proposition for the future, both businesses and investment remain in limbo.
"Companies across the UK are frustrated, but most are still concerned about the prospect of a messy and disorderly exit from the EU. The date may have changed, but the practical questions businesses face remain the same - and the real-world impacts of parliamentary indecision and delay are growing each and every day."