The government labelled the DA's 2012 Cabinet Report Card "mischievous and misleading", after President Jacob Zuma was again awarded an F on Thursday.
Deputy President Kgalema Motlanthe achieved a middling score, and Agriculture Minister Tina Joemat-Pettersson was bottom of the class, according to the report card released by the Democratic Alliance in Cape Town on Thursday.
Acting Cabinet spokesperson Phumla Williams said in a statement it was "clearly a deliberate attack on government, aimed at discrediting its hard work and achievements".
She called on South Africans not to be misled, "but rather rely on government's own performance monitoring and evaluation systems, which are communicated through audited annual reports".
In its report card, the DA found Zuma had failed both his office and South Africa, "and should no longer be entrusted with the presidency".
Briefing the media on the report's content, DA Parliamentary leader Lindiwe Mazibuko said Zuma had "failed comprehensively to provide effective leadership in government".
She blamed Zuma's score on, among other things, the government's "lacklustre response" to the violent mineworkers' strike at Marikana earlier this year, the so-called Nkandlagate scandal, and the country's "lack of economic policy direction".
These issues, and others, were also what motivated the DA, and seven other opposition parties, to table a motion of no-confidence in Zuma last month.
Mazibuko said Zuma's score "stands in contrast to Deputy President Kgalema Motlanthe, who we have awarded a C".
Mazibuko said while Motlanthe was not the top performer in Cabinet, he had "displayed noteworthy qualities which President Zuma clearly lacks".
These included a dedication to the Constitution, an honest approach to the serious challenges facing the government, and a willingness to engage openly with Parliament and South Africans.
At the briefing, DA MP Wilmot James singled out Agriculture, Forestry and Fisheries Minister Tina Joemat-Pettersson for special mention.
"It is worth acknowledging separately the quite disastrous and embarrassing tenure of [this minister], who... received an F.
"Her handling of almost every single matter before her has been so incompetent and negligent that there is no longer any doubt that she should be removed from Cabinet without any further delay."
James later told journalists that when it came to Joemat-Pettersson, if the DA's grading system — which runs from A to F — had gone below an F, "we would have considered that as well".
Other ministers in the 34-member Cabinet who scored an F on the DA's report card include Minister in the Presidency Collins Chabane, Labour Minister Mildred Oliphant, Police Minister Nathi Mthethwa, and State Security Minister Siyabonga Cwele.
Top 2012 performers were Health Minister Aaron Motsoaledi and former science and technology minister Naledi Pandor (who moved to home affairs late in the year). Both received an A.
On Motsoaledi, the report found that under his leadership, the health department had "achieved significant successes in the fight against HIV/Aids".
Pandor had performed "an admirable job of setting and pursuing a clear vision for science and technology in South Africa".