Vauxhall workers face a three month wait to before hearing final plans for their future from potential new owner, Canadian car parts manufacturer Magna.
A spokesman for General Motors Europe said there was no official timeline but the 5,500 workers at Luton and Ellesmere Port, Cheshire said there would be no decision on jobs until GM Europe gets a "definite agreement" from Magna.
Magna and Russia’s state-owned Sberbank will sign an interim deal to take control of the Vauxhall and Opel brands in July, but no final agreement is expected until September.
The Retail Motor Industry Federation (RMIF) has written to business secretary Lord Mandelson on behalf of UK dealers to make sure he considers them during discussions on Vauxhall's future.
RMIF chairman Paul Williams has asked Mandelson to reinforce the size and economic significance of the 500-strong Vauxhall dealer network in the UK, which employs 25,000 people that carry the Vauxhall franchise and its associate brands.