These are the cars that Rover hoped could have pulled Longbridge back from the brink.

The designs for the new models were presented to bosses of both Rover and its prospective partner Shanghai Automotive Industry Corporation (SAIC) less than a month ago.

The designs of three new new models were revealed as administrators said they hoped to restart production at the company's Powertrain engine factory. The move, which could begin as soon as Friday, would safeguard the future of 400 employees for several months.

Designs shown included four- door and five- door saloons, but the vehicles were unlikely to be on the market for at least three years.

Among the designs were a new four door saloon Rover 45 with a new grille and a pedestrian-friendly frontal crash structure; a softer, more conservative four-door version of the Rover 75; and a five-door hatchback.

The hatchback, which is branded both Rover and a more sporty MG version, was aimed at competing with the Volkswagen Golf, Vauxhall Astra and Ford Focus.

It is believed that the new Rover and and MG hatchback models were to be made at Longbridge at an annual rate of 60,000 cars, with 22,000 four-door models a year being built in a new Shanghai factory SAIC has under construction.

According to reports, the Chinese did not fully share Rover's contention that the new mid-sized models needed to be challenging and relatively sporty designs, capable of maintaining their modernity beyond the end of the decade and within days the Chinese had pulled out of the partnership talks.

But Peter Cooke, professor of automotive industries management at Nottingham Business School, questioned whether the new cars could have secured the future of the Longbridge carmaker.

He said: "You have to ask if these cars are different enough, something that will make motorists say 'I want some of that'.

"MG Rover would still be competing in toughest market of all, the mid-size saloon and the hatchback sector.

"Even the big players don't make much profit in that."

Meanwhile, PricewaterhouseCoopers confirmed they were looking to restart production at Powertrain, the engine making sister company of MG Rover.

Powertrain halted production earlier this month when components makers refused to supply more parts and the company was plunged into administration.

But a meeting was held yesterday between suppliers and the administrators to examine ways to recommence work making engines for the Land Rover Freelander and Caterham cars. Rob Hunt, a partner at PwC, said he was hopeful production could resume as soon as possible.

He said: "We need to support the supply businesses. It has always been a case of us trying to retain as much of the business as possible, and we have been in discussions with Land Rover working out the basis on which to carry on.

"Some suppliers will have concerns about the security of their position, but we hope these can be resolved."