The Cabinet strongly criticised the decision - which Jansen said was aimed at promoting racial reconciliation - describing how it came about as flawed.
Government spokesman Themba Maseko told journalists yesterday: "The process that led to the dropping of the charges was flawed in that it did not follow the established norm of getting the perpetrators to admit guilt, to apologise to the victims before any charges could be dropped and to initiate a reconciliation process."
Maseko said the Cabinet backed Higher Education Minister Blade Nzimande's call for Jansen to suspend his decision and initiate an inclusive consultative process on the issue and on racism at the university.
Jansen's decision has been criticised heavily by the ANC, Cosatu and a range of student organisations on the Free State campus and around the country.
Cosatu went so far as to call for Jansen's head, a move supported by more than 500 University of Free State students, who have joined a growing Facebook group called "Jansen is a sell-out".
The four former students of the now-closed Reitz men's residence are accused of filming a mock initiation of five black cleaners into hostel activities.
The students - RC Malherbe, Johnny Roberts, Schalk van der Merwe and Danie Grobler - will go on trial for crimen injuria on Monday.
Free State students affiliated to the SA Students' Congress said they planned to stay away from classes on Monday and would apply for permission to march on the Bloemfontein Regional Court.
Yesterday, the majority of more than 250 students at a meeting said they were in favour of a strike.
Sasco spokesman Thapelo Lekwene said: "The students went to Jansen's office where they demanded he address them. He came out and tried to explain his decision, but they were still not satisfied with his answers."
Mothusi Lepheana, the Human Rights Commission official representing the five cleaners, said some of them would attend the court case, but not all of them had recovered from their 2007 ordeal. - Additional reporting by Sapa
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