[1] In January 2017, Tony Pua, the plaintiff in the High Court and the appellant here ('Tony Pua'), brought an extraordinary claim against the then (and now former) Prime Minister of Malaysia, Dato' Seri Najib bin Tun Abdul Haji Razak ('Najib Razak') and the Government of Malaysia ('Government'), premised on the common law tort of misfeasance in public office.

[2] The thrust of the claim was that the then Prime Minister, Najib Razak, had committed misfeasance in public office in relation to a sovereign fund established for the economic benefit of Malaysia and the Malaysian people, known as 1MDB. More particularly, it was alleged that the then Prime Minister had abused his public office by personally benefitting and/or profiting from the receipt of monies from the 1MDB fund, comprising public funds.

[3] In response to this claim, the defendants, both Najib Razak and the Government, sought to strike out Tony Pua's claim under O 18 r 19(1)(a), (b), (c) and (d) of the Rules of 2012 and under the inherent jurisdiction of the Court.

[4] In the High Court, the claim was struck out summarily under O 18 r 19(1)(a) for a variety of reasons. For the purposes of these appeals, the primary ground