The future of Longbridge is descending into a soap opera which may not have a happy ending, Trade and Industry Secretary Alan Johnson warned yesterday.
Mr Johnson was in the Midlands to see how the region was coping with the aftermath of the MG Rover collapse. He said he had been assured in good faith by Rover's new owner Nanjing Automobile that it still planned to build some cars at the Longbridge site.
But he acknowledged that delays to the announcement of the firm's plans were proving damaging.
Mr Johnson said: "With regards to Nanjing we do not know what is going on. I have been talking with Birmingham council leader Mike Whitby who met with Nanjing recently.
"Nanjing told him they were acting in good faith and nothing had changed in relation to their plans to create jobs at Longbridge within 18 months."
But Mr Johnson said he remained sceptical about what Nanjing would do, citing the company's need to secure a partner - a problem which blighted the last days of MG Rover and ensured its ultimate demise.
He said: "It would be such a terrible thing to get people's hopes up about a return of car production at Longbridge and that to be dashed.
"Most people have a healthy scepticism; I think that is right. If it does happen I will be delighted, but we have to plan for it not happening.
"It is all becoming a bit of a soap opera really and we should not bank on a happy ending."
Mr Johnson said he was sure that Nanjing had a business plan and the Department of Trade and Industry would help in any way possible.
"They have a business plan, but they are not keen to reveal it. They are a private company and we are looking to get them into the UK.
"But they have a court case with Shanghai Automotive Industry Corporation to sort out. We can help them with training and with helping them find their way around the West Midlands." He said he would continue to monitor developments in Southwest Birmingham and supported the use of the Longbridge site for manufacturing.
He said: "My ambition is to keep as many manufacturing jobs as possible there. I see this as one of the major areas for manufacturing."
Earlier, Mr Johnson met with families of Rover workers and members of the MG Rover Task Force to discuss their report Six Months On which was published yesterday.
The report detailed how the impact of MG Rover's closure on the West Midlands economy had been successfully limited.
As a result of interventions, approximately 9,000 jobs - 5,850 of which were MG Rover workers - will be lost instead of the 13,000 originally estimated.
Mr Johnson said: "The collapse of MG Rover was a severe blow for the workforce, the automotive sector and the community.
" But the region has coped extremely well and has exceeded expectations."