Celebrity chef Jamie Oliver is closing six of his 42 UK Jamie's Italian restaurants.
The Aberdeen, Cheltenham, Exeter, Tunbridge Wells and in London, the Ludgate and Richmond outlets are all scheduled to close soon.
The move will affect 120 staff, whom the company said it would try to place in other parts of the chain.
The company said that the market was "tough" and the uncertainties caused by Brexit had intensified the pressures.
The price of ingredients bought in Italy has gone up because of the fall in the value of the pound against the euro since the vote to leave the EU.
Chief executive Simon Blagden said: "As every restaurant owner knows, this is a tough market and, post-Brexit, the pressures and unknowns have made it even harder."
He said each restaurant in the chain needed to attract 3,000 diners a week to be profitable.
Jamie's Italian has 28 overseas outlets and the company also said it planned to open another 22 outside the UK.
Last year, Jamie Oliver said he would buy back the Jamie's Italian restaurants business in Australia.
He moved after Keystone Group, which ran the operation, went into receivership and put the franchise up for sale.