Rover's critics have been accused of helping to destroy it.
Richard Burden, the MP whose constituency includes the Longbridge car plant, said the firm lost sales because of constant sniping by media critics.
Rover workers were angry about the way the carmaker had been portrayed, he said.
Mr Burden (Lab Northfield) also suggested Rover could have survived if the Government had accepted calls for limited re-nationalisation.
Rover was once part of British Leyland, the state-owned car manufacturer, and MPs including Mr Burden called in recent years for Ministers to buy back a stake in the company.
Speaking in the House of Commons, he said an "endless stream" of criticism of Rover "probably ended up getting in the way of proper scrutiny rather than promoting it".
He added: "Whatever the 'Phoenix Four' may have been responsible for, I also believe the endless public belittling of MG Rover also played a role in depressing both sales and confidence and hastening the company's demise.
"Make no mistake, there is still real anger about that amongst former MG Rover employees."
The 6,100 former Rover workers wanted to know why the firm had gone so wrong after it was bought from BMW five years ago, he said.
"Not so much about the fact that MG Rover was not able to survive. Everyone knew that for long term future, the company needed a partner.
"That was clear and openly stated from when Phoenix took over in 2000. It was equally clear from that time that there was never any guarantee this would happen. The issue is much more the manner in which the collapse took place and what led up to it.
"Just why did the talks with Shanghai Automotive Industry Corporation finally come to nothing?
"Had people been misled?
Was there something fundamentally wrong with way Phoenix Venture Holdings had structured its businesses and run their affairs?"
Mr Burden said he backed the decision by Alan Johnson, the Secretary of State for Trade and Industry, to order an official investigation. But he demanded there must be no "no go areas" - and its results must be made public.
He added: "The Phoenix Directors would, I am sure, like to be remembered for helping to buy that time for the region whilst pursuing a brave but, ultimately unsuccessful strategy for MG Rover."