Around 1700 jobs are at risk after sports retailer and gym group DW Sports fell into administration.
On Monday, the company was expected to appoint insolvency specialists after its income was hit by the closure of stores and gyms during lockdown.
DW Sports, which was founded by former Wigan Athletic owner Dave Whelan, operated 73 gyms and 75 retail sites across the UK but announced plans to shut 25 of its stores last month.
Currently, 59 of its gyms have reopened in England and Northern Ireland, with a further 14 sites in England, Scotland and Wales unable to open due to Government restrictions.
The company said it will now wind down its retail business for good, with its website ceasing trading with immediate effect and closing-down sales starting at its 50 remaining stores.
The company plan to protect as many jobs and gyms as possible through restructuring.
DW Sports said Fitness First, a sister company of DW, will continue to operate as a separate company and its 43 clubs will be unaffected by the administration.
Administrators intend to support employees, customers and gym members as far as possible while they look to secure a buyer or buyers for some or all of the DW Sports portfolio.
Chief executive Martin Long said: “As a consequence of Covid-19, we found ourselves in a position where we were mandated by Government to close down both our retail store portfolio and our gym chain in its entirety for a protracted period, leaving us with a high fixed-cost base and zero income.
“Like many other retail businesses, the consequences of this extremely challenging operating market have created inevitable profitability issues for DW Sports.
“The decision to appoint administrators has not been taken lightly but will give us the best chance to protect viable parts of the business, return them to profitability, and secure as many jobs as possible.
“It is a difficult model for any business to manage through without long-term damage, and with the limited support which we have been able to gain.
“Having exhausted all other available options for the business, we firmly believe that this process can be a platform to restructure the business and preserve many of our gyms for our members, and also protect the maximum number of jobs possible for our team members.”