Amwano started his parliamentary career in 1998, when he won a vacated seat in a by-election for the Ubenide Constituency following the resignation of former president Lagumot Harris.

He was one of three non-Cabinet government MPs to switch to the opposition after benefiting from a trip to Singapore organised and paid for by the Australian company Getax, which buys Nauruan phosphate.

[5] On 6 July, opposition MP Rykers Solomon joined the government, potentially giving it the numbers to re-elect Stephen, or to elect a new president from within its ranks.

The Australian Federal Police investigated the allegations that Getax had bribed Nauruan MPs "to influence the political regime in Nauru in order to increase their stake in the country's phosphate".

Amwano spoke up to defend Getax, denying any wrongdoing and adding that he "would be happy for the Australian Federal Police to investigate".