The two Michelin-star chef restaurateur believes that a combination of very few tourists, Londoners holidaying elsewhere in the UK and a general downturn in eating out could leave his two dining rooms at Chelsea's Michelin House half full.
"We need to turnover £200,000 a month to break even. I don't think London is going to be busy enough to keep the place going. My wage bill is high."
"If I open both of them only running at 50% we'll be gone in two months. It's better to continue with the furlough scheme," says Bosi, who is planning a revamp of the Oyster Bar's menu.
"I want to make the Oyster Bar much better. We're going to put a lot of time and attention into it," he says.
When Claude Bosi does re-open on 8 September it will be open for dinner Tuesday to Sunday with lunch only offered on Saturday and Sunday.
The restaurant will also switch from eight starters and eight main courses to five starters and five main courses to reduce staff and ingredient costs.
Some of Bosi's European staff have elected not to return. The smaller team will now work across the two restaurants, which Bosi says makes sense because the Oyster Bar - in contrast to his flagship - is much busier for lunch as it is for dinner.
Bosi launched a takeaway offer early this month that included some ready to eat food and some meals to prepare at home."
We wanted to start re-opening the place, to get some momentum going. And keep the place alive from a social media perspective," he says.
"Of course we wanted to make money with it, but in the end we haven't. We break even, I pay for the food and I pay for the staff. That's it."
Bosi will pause his takeaway offer next week as he gears up for the Oyster Bar's re-opening, but he plans to bring it back when the restaurant is fully up and running, probably mid-July."
Every business is going to find themselves doing takeaway and delivery to cover the decline in eat-in," he says.
"As much as people are excited about restaurants reopening we still don't know what is going to happen. Look at the new cases in Germany. If we opened upstairs and downstairs at the same time and that happens it could kill the business."
A full podcast with Claude Bosi will be published next week.