The Inclusive Society Institute (ISI) has called on President Cyril Ramaphosa to refer the Electoral Amendment Bill to the Constitutional Court for a decision on its constitutionality before signing it into law.

The National Assembly passed the controversial bill, necessitated by a Constitutional Court ruling that independent candidates must be allowed to stand in provincial and national elections, on 23 February.

Ramaphosa is yet to sign the bill, despite the Constitutional Court's suspension of its order of invalidity on the Electoral Act to 28 February, after Parliament approached it twice for extensions.

In a statement, the institute says it has written to Ramaphosa to raise its concerns about the bill and has submitted legal opinions that the bill may not pass constitutional muster in its current form.

"The ISI has participated fully in the public hearings of both the National Assembly and the National Council of Provinces, laying out in detail their concerns with the Bill. The Institute believes that the Bill treats independent candidates unfairly, giving an advantage to candidates from political parties. While the legislature has mitigated some of their concerns, in other areas, the institute feels that the Bill remains unconstitutional," reads the statement.

"If the Bill is signed into law, the ISI may be faced with a moral and ethical dilemma as to whether to knowingly sit back and allow for an election to take place in terms of unconstitutional legislation or challenge its validity. The ISI believes that this challenge could create logistical problems for the execution of a timeous, free, and fair election, given the timeframe ahead of the 2024 election."

The institute, which has several ANC-aligned people on its board and advisory council, has called on Ramaphosa "to take a prudent approach and carefully consider the constitutionality of the Bill before signing it into law".

"The institute urges the president to exercise his rights in line with Section 84(2)(c) of the Constitution of the Republic of South Africa by referring the Bill to the Constitutional Court for a decision on its constitutionality," it said.

The bill has faced much criticism from various civil society organisations, which has mooted litigation since it was put to the vote for the first time in the National Assembly in October last year. A general concern is that the bill does not allow a mixed constituency-proportional list system.

After the National Assembly passed the bill, the National Council of Provinces made further changes. Chief among the changes is a clause providing for the establishment of a panel of experts to consider more comprehensive electoral reform than what the current bill provides for.

This required an extension of the deadline to 28 February.

In its 11 June 2020 ruling, the apex court declared the Electoral Act unconstitutional "to the extent that it requires that adult citizens may be elected to the National Assembly and provincial legislatures only through their membership of political parties".

The Constitutional Court suspended the declaration of unconstitutionality for "24 months to afford Parliament an opportunity to remedy the defect giving rise to the unconstitutionality".

This means the initial deadline to pass the legislation was 10 June 2022.

Parliament initially deferred working on the amendment to the Department of Home Affairs, and the bill was only introduced to Parliament in January 2022.

The Constitutional Court extended the deadline for the bill's enactment to 10 December after Parliament approached the apex court for a deadline extension when it became clear it would not reach the original cut-off date.