A chamber of commerce has said if it takes "a while" for Jaguar Land Rover to reach full production, it might take months "for that to filter down into the supply chain".
JLR has stated it would resume some production in the "coming days" after a cyber-attack forced the carmaker to suspend operations.
At the weekend it emerged the government will underwrite a £1.5bn loan guarantee to the company in a bid to support its suppliers.
Chief executive of Coventry and Warwickshire Chamber of Commerce Corin Crane said it saw in its survey one in six businesses were already making redundancies.
