A Cabinet Office spokeswoman told PRWeek that The Crown Commercial Service, which looks after the Government’s framework of rosters spanning marcoms, was "confident" that the remaining five PR agencies on the Lot 4 PR roster would be sufficient.
The framework launched last year following a lengthy application process, with Unity appointed alongside Engine Group, Munro & Forster, Consolidated, SKV Communications and Syndicate Communications.
However, Unity quit the line-up earlier this month, with co-founder Nik Done claiming the process was too focused on previous experience.
Calling the set-up "fundamentally flawed", she also attacked the frameworks for encouraging partnering with other agencies.
It is understood that since the departure, the government has been approached by at least one other agency to fill the vacancy.
The Cabinet Office spokeswoman said: "The Crown Commercial Service is confident that the remaining suppliers on Lot 4 will continue to provide for customer requirements.
"Although we will not be replacing Unity on the agreement we are always keen to hear from suppliers that want to do business with the public sector."