Vauxhall dealer Crown Motors, which has sites in Romford and Dagenham, has gone into administration.
Trading at both dealerships has ceased while administrators Greg Palfrey and David Blenkarn of Smith Williamson attempt to find buyers.
Almost all of the group’s 70 members of staff have been laid off.
Earlier this month, Vertu Motors bought Crown’s Vauxhall and Chevrolet dealership in Ilford for £80,000.
Customers are being directed to Vauxhall dealer Tony Levoi based in Grays, Essex for service.