Helen Suzman Foundation (HSF) director Francis Antonie said they would argue for confirmation of the order of the Western Cape High Court judgment on Thursday.
The HSF had also launched an appeal to declare invalid other provisions of the act that were not dealt with by the court.
“We maintain that independent anti-corruption units are a vital part of the institutional state apparatus in South Africa,” Antonie said.
In December, Judge Siraj Desai ruled that sections of the act were “inconsistent with the Constitution and invalid to the extent that they failed to secure an adequate degree of independence for the Directorate for Priority Crime Investigation [the Hawks]”.
He suspended the declaration of constitutional invalidity for a year for Parliament to rectify the defects.
The amendments to the act were drafted following a previous Constitutional Court victory by businessman Hugh Glenister, in which the executive was ordered to change the legislation to, among other things, provide the Hawks with independence from political interference.
Glenister brought his suit following the dissolution in 2008 of the Scorpions, an investigative unit which fell under the jurisdiction of the National Prosecuting Authority.
The Scorpions, or the Directorate of Special Operations, was replaced by the Hawks, which now falls under the police.
The HSF challenged those parts of the amendment act relating to the structural and operational integrity and independence of the Hawks.
Desai found that the appointment process of the Hawks’ head vested an “unacceptable degree of political control in the minister [of police] and the Cabinet”.
The minister’s power to extend the Hawks head’s tenure was “intrinsically inimical to the requirement of adequate independence”.
The suspension and removal process not only vested an inappropriate degree of control in the minister, but also allowed for two separate and distinct processes “determined on the basis of arbitrary criteria, each able to find application without any reference to the other”.
Desai also found that there was an unacceptable degree of political oversight in the jurisdiction of the Hawks, and that the relevant provisions were so vague that “not even those responsible for their implementation are able to agree on how they should be applied”.
Antonie said the respondents President Jacob Zuma, Police Minister Nathi Mthethwa, Hawks head Anwa Dramat, and the government had appealed Desai’s judgment.
He said the Constitutional Court would hear both the confirmation and appeal applications.