Senator Amanda Vanstone provoked a storm of protest from both the public and private sectors when she said students from government secondary schools were 10 times more likely to end up in dole queues than private school-leavers.
"The bottom line is that for school-leavers, private schools have beaten unemployment," the minister said in a speech in Adelaide.
She quoted data compiled by the Australian Bureau of Statistics that showed the unemployment rate for male school-leavers who had attended government schools was 14 per cent at the end of 1995, compared with 2 per cent for students from private schools.
Only 1 per cent of girls who had been to private schools were out of work at that time, Senator Vanstone said. But as the critics pointed out, apart from the fact that private school students tend to come from better-off homes in areas where unemployment is low anyway, 60 per cent of the students go on to university - compared with fewer than 50 per cent of government school students.
While not censoring Senator Vanstone, Mr Howard said she had not appreciated the difficulties faced by government school students. He said he did not agree with the "negative spin" the minister had put on the bureau's figures.
"Those sort of comparisons do not make proper allowance for some of the circumstances in which government schools have got to operate," the prime minister said.
Describing himself as a product of the government education sector, Mr Howard said that Australia had a strong public school system that would be maintained and nurtured by his administration.
But teacher unions and the federal opposition called on Mr Howard to sack the education minister. The opposition education spokesman, Mark Latham, said Senator Vanstone should resign because she had lost the support of the education sector.
"The minister has unfairly placed a stereotype and stigma on every government school in Australia, showing again why she is the minister against education, rather than for it," Mr Latham said.
A senior official of the Australian Education Union said the Howard government's rhetoric and its policies showed that it was ideologically opposed to the provision of a universal, free public education system.