The company brought forward the launch of the 200 series to the London Motor Show amid concern about flagging sales and reports that its German owner, BMW, had lost patience with Rover's performance.
The 200, the last car to be developed under Rover's collaboration with Japan's Honda, replaces the stale Rover 200 hatchback. With modern, youthful styling the success of the new-look car is vital for Rover's success in Europe's biggest and most competitive sector - the small family car market.
The 200 series goes on sale in December at between pounds 10,000 and pounds 16,000. With the new 400 series five-door launched this year, and the 400 saloon also being unveiled at the show, Rover has never been so strong in the mid car market.
Its chief executive, John Towers, said: "This is our strongest presence in the medium sector. Within 12 months we have transformed our range." The 200 comes with a 1.4 and 1.6 litre engine, and also with the 1.8 litre engine recently launched in the Rover MGF, the revived classic roadster that has been the talk of the motor industry.
The MGF, launched at the Geneva Motor Show in March, also gets its first UK viewing today, though it too faces intense competition in a crowded sports car market.
Fiat's Barchetta and Alfa Romeo's Spyder both make their UK debuts, as does the long-awaited Lotus Elise lightweight racer, retailing at just pounds 20,000.
Rover, despite its investments in marques, faces a tough task. The company's UK market share has fallen from 12.4 per cent to 11.3 per cent in the first nine months of this year, and the company has done little better in continental Europe.
Rover is untroubled by the fall, arguing that it expects to lose market share as its models go upmarket. Whether that strategy works depends on the public's reaction to what is on offer at today's show.