Costa Coffee has said around 1,650 roles are at risk of redundancy across its sites due to the ongoing impact of Covid-19.
The coffee chain said the trading environment "remains challenging" and "has required the business to make difficult decisions to ensure that as many jobs as possible are protected long-term".
More than 2,400 of its 2,700 stores have reopened, and while Costa said trade is returning, helped by the government's VAT reduction and the Eat Out To Help Out scheme, there remains high levels of uncertainty as to when trade will recover to pre-Covid levels.
The group has therefore launched a consultation process where it said it will seek to find alternative roles for staff where possible, and support those leaving the business.
Neil Lake, managing director for Costa Coffee UK and Ireland, said: "Today's announcement to our store teams was an extremely difficult decision to make. Our baristas are the heart of the Costa business and I am truly sorry that many now face uncertainty following today's news.
"We have had to make these difficult decisions to protect the business and ensure we safeguard as many jobs as possible for our 16,000 team members, while emerging stronger ready for future growth.
"As a proud member of the UK high street, we remain committed to the role Costa plays in supporting the economic recovery of the country, but today I want to say a huge thank you to all of our team members that are affected by this announcement and we will be supporting you throughout this process."
Costa employs 16,000 people across 1,600 owned UK stores. In addition, there are 1,100 Costa franchise stores across the UK employing 10,500.