It explained, in a report on 16 May on its website:
“Najib’s legal action was initiated in his personal capacity and jointly with Umno through law firm Hafarizam Wan & Aisha Mubarak.”
Mr Najib is also president of the United Malays National Organisation (UMNO).
Malaysiakini added:
“A letter of demand, which was hand-delivered to Malaysiakini late yesterday, claimed the compilation of readers’ comments in two ‘Yoursay’ articles published on May 14, namely ‘A case of the PM reaping what he sows’ and ‘How much will Najib spend to keep Terengganu?’, were defamatory.”
Lawyer for Umno, Mohd Hafarizam Harun, said, “All the accusations made by users on Malaysiakini.com were totally baseless, without concrete proof and are very serious, on top of having ill-intent (mala fide) to damage the reputation and image of our clients.”
The lawyer added, “The said defamatory and seditious articles are not responsible journalism as you are aware that the republication of the baseless defamatory allegations made by the users of Malaysiakini.com will have negative impacts towards our clients as it is spreading hatred, contempt and ridicule and it ruins the credibility of our clients.”
Mr Najib and UMNO are demanding that Malaysiakini “withdraw the offending articles from their website and publish an unconditional written apology based on terms agreed by them.”
Malaysiakini has been give 48 hours to comply or face court proceedings instead, the lawyer’s letter said.
Editor-in-Chief of Malaysiakini, Steven Gan, said the website “had expected such action after Umno-owned Utusan Malaysia attacked Malaysiakini readers last month”, referring to the Malaysian newspaper which is controlled by the Malaysian government.
Mr Gan was reported as saying that “the news portal, as always, will offer Najib the right of reply and to engage Malaysiakini readers.”
“He is more than welcome to explain to them why he thinks their opinions of him and Umno are wrong,” said Gan.
He said the prime minister and Umno should present their views, which will be published in Malaysiakini, rather than threatening media organisations with libel proceedings.
It is unclear which comments Mr Najib and UMNO are taking issue with.