Roumen Gechev, deputy prime minister, said the project's demise was because the Rover Maestro cars being produced were uncompetitive and there was no marketing strategy.
He said allegations made last week that bureaucratic obstacles and a lack of government support were behind the collapse of the Rodacar joint venture were untrue.
"Claims that the government contributed to Rodacar's failure are absolutely groundless," Mr Gechev said, adding that the government had no contractual commitment to buy the Maestros.
Vincent Hammersley, a Rover official, had said that the government's failure to order Maestros for its own fleet, despite assurances that it would do so, had hit the company.
He said last week that the Bulgaria plant would close at the end of May after selling only about 200 of more than 2,000 Maestro vehicles that had been imported for assembly in the country.
Rodacar was launched a year ago when Rover, a division of Germany's BMW, invested $20m (pounds 13.3m) for a 51 per cent stake. A private Bulgarian consortium, Daru Group, owned the remaining 49 per cent of the venture, which was to be a launch pad into other east European countries. Last month Daru hit financial difficulties, and its banking operation was rescued by the state bank.Reuse content