Mitchells and Butchers, which owns Harvester, All Bar One, Toby Carvery and O'Neills, has begun redundancies consultations with staff amid struggles brought on by social restrictions, the BBC has reported.
The chain operates around 1,700 pubs and restaurants across the UK, employing around 44,000 people. It is unknown how many employees will be affected.
According to the BBC, a Mitchells and Butchers spokesman said the company would 'seek to redeploy affected staff wherever possible'.
"Our industry is operating in exceptionally challenging and uncertain circumstances," said the spokesman.
"While we have worked incredibly hard to make sites Covid-19 secure and keep staff and customers safe, we are facing significant difficulties from the recently introduced 10pm curfew for pubs, bars and restaurants, new enforced closures and tapering government support that doesn't go far enough.
"With trading restrictions and uncertainty likely to continue for the foreseeable future, we strongly urge the government to step up the level of support it is offering to an industry which has been repeatedly singled out and taken the full brunt of restrictions."
In East Sussex. Eastbourne currently has one Harvester restaurant, The Sovereign Harbour, in the Waterfront, as well as one Toby Carvery in Willingdon Drove.
East Sussex also has Harvesters in Brighton Marina and Madeira Drive in Brighton, as well as an All Bar One in the Pavilion Buildings in Brighton city centre.
West Sussex has Harvesters in Crawley Leisure Park, The Barn, in Chichester and The Britannia in Grinstead Lane, Lancing.
There is also The Beech Hurst in Beechurst Gardens, Haywards Heath, and The Windmill in Littlehampton.
Worthing's Toby Carvery could also be in danger of job cuts.