Unconstitutional and now invalid.

This was the ruling of the Supreme Court of Appeal (SCA) on a piece of legislation, which stated that individuals would cease to be South African citizens if they acquired the citizenship or nationality of another country through a voluntary and formal act other than marriage.

In terms of the legislation, citizens had been required to get permission from the home affairs minister to retain their citizenship.

The SCA on Tuesday ruled in favour of the Democratic Alliance (DA), which had appealed an order by the Gauteng High Court in Pretoria.

The minister and director-general of home affairs were respondents in the SCA ruling.

The DA challenged the constitutionality of section 6(1)(a) of the South African Citizenship Act 88 of 1995 on behalf of South Africans who unknowingly lost their citizenship after acquiring second citizenship in other countries.

SCA Judge Dumisani Zondi said in his ruling: "The Act simply fails to provide a coherent basis as to how dual citizenship may be recognised as permissible and unobjectionable, but also warrants the drastic consequence of the loss of South African citizenship in terms of s 6(1), save for the exercise of ministerial discretion. The statutory scheme is indefensible and the impugned provision is irrational."

The DA built its case using the evidence of a South African, Phillip James Plaatjes, who is living in the UK. 

Plaatjes married a British citizen while working in South Korea in 2004. 

The couple moved to the UK, where he obtained his British citizenship in November 2007.

The DA said that, in 2015, the South African embassy informed Plaatjes that he had lost his citizenship when he went to renew his passport. 

He alleged he had used the document to travel between 2007 and 2014.

The party said he was one of many citizens who, unknowingly, lost their citizenship after acquiring a second nationality.

The high court initially ruled against the DA, saying the act allowed the state to regulate citizenship and dismissed the party's argument that it was invalid.

It also ruled that the citizens acquired secondary citizenship voluntarily.

The department had also argued that the citizens did not wish to retain their South African or dual citizenship.  

Zondi took a different view, with Judges Ashton Schippers, Elias Matojane, Fayeeza Kathree-Setiloane and David Unterhalter concurring with his judgment.

His ruling noted that the act took effect in 1995 when the interim Constitution was still in force. 

It said the act remained in place, even after the interim Constitution was repealed by the current Constitution in 1997.

Zondi said citizenship was an important right, which brought with it many benefits.

He said:

To deprive persons of this right, with no regard for their individual circumstances and the reasons that they are taking out another citizenship is both unfair and capricious. The legislature is not against dual citizenship we were told. If that is so, why take away South African citizenship by automatic operation of law, and require that its retention depends upon the invocation of a ministerial discretion that is entirely unspecified as to what its exercise is intended to achieve?

He found section 6(1)(a) of the Act was irrational and inconsistent with the Constitution.

"It also unjustifiably limits political rights, the right to enter and remain in the Republic, and the right to freedom of trade, occupation and profession, guaranteed by the Constitution."

Zondi ruled that section of the Act was no longer valid and he did not impose a suspension of his order.

"It is further declared that those citizens who lost their citizenship by operation of s 6(1)(a) of the South African Citizenship Act 88 of 1995 are deemed not to have lost their citizenship."

The DA welcomed the ruling.

"After a nine-year-long campaign by the DA Abroad and a five-year court battle by the DA, the judgment of the SCA is a victory for the constitutional right to citizenship," it said in a statement.

"This provision is in fact carried over from an apartheid-era Citizenship Act, which was used by the apartheid government to strip exiled freedom fighters and those taking citizenship of bantustans of their South African citizenship without their knowledge. 

"It doesn't belong in our constitutional democracy. If the African National Congress is serious about ridding our legislation of apartheid statutes, they will not appeal this judgment."

Comment from the home affairs department will be added once received.