General Motors has warned that the unit would go under without official help.
"Voters picked me because they wanted nursery schools, police and nurses, and not to buy loss-making car factories," Enterprise and Energy Minister Maud Olofsson told Swedish public radio.
Her comment came after GM late Tuesday presented a massive restructuring plan to the US Treasury and said its troubled Saab unit could file for bankruptcy protection "as early as this month" without support from the Swedish government.
The company said last year it planned to try to find a buyer for the brand.
"They're basically saying they think the Swedish government should take over Saab, but if we do that we're talking about an incredible amount of money," Olofsson said
She contended that that Saab had been loss-making for much of the past 20 years it has been under GM control.
"I'm disappointed in General Motors, because they're abandoning Saab and are pushing the responsibility over to Swedish tax payers, and I think that is irresponsible," she said.
While Sweden's centre-right government has refused to take over Saab it has nonetheless said it will act as a guarantor for a European Investment Bank (EIB) loan of five billion kronor (450 million euros, 566 million dollars) to help keep car maker afloat.
The opposition meanwhile insists that that is not enough, calling for the government to pump state funds into Saab.
"A heavy responsibility rests on the Swedish government," Tomas Eneroth,
the economic policy spokesman for the main opposition Social Democrats, told
the TT news agency.
Saab, which after years of dwindling sales went into full crisis mode with the global economic downturn, employs some 4,100 people in Sweden, 3,700 of whom work at its hub in the southwestern town of Trollhättan.
According to the unions, some 15,000 jobs in Sweden would be at risk if the unit were to disappear, since its suppliers would also be hard-hit.
"We are worried, but GM has said it will continue to try to find a solution for Saab," IF Metall union representative Paul Åkerlund told AFP.