Glasgow and Moray will remain in Level 3 of the five-tier system of coronavirus restrictions on Monday for at least another week as the rest of the mainland drops to Level 2.
A drop to Level 2 would mean widespread relaxations over rules in hospitality and entertainment, including venues being able to serve alcohol indoors and the reopening of cinemas, theatres and casinos.
Andrew McRae, the Federation of Small Businesses Scotland policy chairman, said the news was “crushing” for businesses and their customers.
He said: “The damage of this change, especially in Glasgow, is exacerbated by the lateness of this announcement.
“It means wasted stock, disappointed customers and increased debt.
“Scotland’s largest city has faced tough restrictions for months and months, doing untold harm to local firms.
“While the action proposed may or may not be necessary, pushing it out the door at close of play on a Friday will further undermine independent businesses.”
Michael Bergson, managing director of Buck's Bar Group in Glasgow, said the announcement was a “serious financial blow” to the industry.
"We are frustrated because it’s a disproportionate response to the rise in cases,” he said.
"We are not seeing hospitalisations or deaths with these new cases, and the hospitality sector is being made to suffer even when the cases aren’t linked to the industry.”
Mr Bergson added: “Pubs and restaurants will have prepped fresh food and had staff rotas all ready for Monday.
"It’s shocking that they can make this sort of announcement just 72 hours before the day we were told we could reopen.”
Mario Gizzi, owner of The DRG group which owns brand such as Di Maggio’s and Cafe Andaluz, called it an “absolute disgrace”.
He said: “Not only have our plans been thrown up in the air but it’s been done last thing on a Friday night.
“At just one of our sites, The Citizen in Glasgow, we’ve spent more than £6,000 in staff costs getting ready and roughly the same in fresh produce.
“As a standalone unit, all this food will be wasted and can’t be transferred to another restaurant.
“It’s outrageous to have these hugely damaging decisions taken by people who have no idea of how the hospitality industry runs.”
The Scottish Government has said affected businesses will receive additional financial support – of up to £750 per week, which Mr Gizzi labelled a “joke”.
Meanwhile, the Scottish Hospitality Group said it had asked the Scottish Government for advance warning of any changes on Wednesday and “did not get anything back”.
Spokesman Stephen Montgomery said: “We’re in exactly the situation we wanted to avoid for the hospitality businesses in Glasgow.
“Here we are a full year on and it seems decision-makers have learned nothing and it’s shameful to be treating people this way.
“Staff are getting ready for their shifts, or have been working flat out to prepare for opening, and have ordered stock. You can’t just turn this stuff on and off like flicking a light switch.”
The latest figures published on Friday showed there were 80.4 cases per 100,000 people in Glasgow in the seven days to May 11, pushing it ahead of Moray where there were 68.9.
Glasgow Chamber of Commerce chief executive Stuart Patrick said the move was “deeply disappointing”.