It follows speculation last week that TRG is preparing to close between 100 and 120 sites in its leisure arm, which includes the Frankie and Benny’s, Garfunkel’s and Chiquito chains.
An email sent to TRG staff and seen by the BBC said that many sites were no longer viable to trade, and would remain closed permanently.
“The Covid-19 crisis has significantly impacted our ability to trade profitably, so we’ve taken the tough decision to close these restaurants now,” the email said.
“Unfortunately, unless there are any suitable alternative roles identified, it’s likely your role will be made redundant."
It is thought that between 2,000 and 3,000 employees could lose their jobs as a result of the closures.
Responding to last week's reports, TRG said: "As is widely understood our industry is facing exceptional challenges in what is an unprecedented operating environment. The casual dining sector was already facing significant challenges prior to the onset of Covid-19, with overcapacity and significant cost pressures.
"In order to meet both the immediate challenges and to build a post-lockdown business with a sustainable future, we are in discussions with our landlords regarding potential restructuring options for our leisure estate."
The group, which is one of the UK's largest restaurant operators, added that its Wagamama, airport concessions and pub operation divisions would not be affected by these discussions.
Prior to the pandemic TRG's leisure arm was already facing a notable struggle, having announced in February that it was to cut the size of its estate from 350 sites to 260-275 by the end of 2021.
The group has already closed 61 of its 80 Chiquito restaurants due to the pandemic, having placed the Tex-Mex chain in to administration in late March.
At the same time, TRG also appointed administrators for its 11-strong Food and Fuel gastropub group, with all sites closed permanently.
