Following an unsuccessful bid for the premiership in December 2010 (with Toafa's support), he became leader of the Opposition to prime minister Willy Telavi's government.

He then served as the Permanent Secretary (the highest civil service position) and European Union National Authorizing Officer within the Tuvaluan Ministry of Foreign Affairs and Economic Planning from 1992 to 1995.

Sopoaga, who was elected to parliament for the Nukufetau constituency was expected to pose a strong challenge to Ielemia for the office of prime minister during the formation of a new government.

The motion was reportedly due to MPs' concerns about the budget, and in particular possible restrictions on the government's funding of Tuvaluans' medical costs abroad.

He continued to call for international initiatives to tackle climate change, including "adaptation techniques", a transfer of affordable sustainable technologies to vulnerable developing nations.

One other issue he raised during a talk on Radio Australia was the need for independent media in Tuvalu, presenting news in an accurate rather than "rosy", 'pro-government' manner.

[19] In early 2012, he criticised the Telavi government's decision to establish formal diplomatic relations with "countries that have unsettled political issues of concern to the international community" – namely, Abkhazia, South Ossetia, and Armenia (the latter in the context of its territorial dispute with Azerbaijan).

[20] Sopoaga became prime minister in a caretaker capacity following the dismissal of incumbent Willy Telavi by Governor-General Iakoba Italeli on 1 August 2013.

[3] In a secret ballot held during an extra session of parliament three days later, Sopoaga was elect as Prime Minister of Tuvalu by 8 votes to 4.

[23][24][25] Enele Sopoaga said his administration will focus on working to make Tuvalu less vulnerable to climate change and global economic forces.

[25] Enele Sopoaga as Minister for Public Utilities and Infrastructures launched Tuvalu Atoll Science Technology Training Institute (TASTTI) on 20 December 2017.

He proposed amending the draft climate treaty so as to require all countries to limit the rise in global air temperatures to 1.5 degrees Celsius above pre-industrial levels.

[37] As prime minister, Enele Sopoaga has worked on international effects to address the problems resulting from global warming in Tuvalu.

"[41] Prime minister Enele Sopoaga said at the 2015 United Nations Climate Change Conference (COP21) that the goal for COP21 should be a global temperature rise of below 1.5 degrees Celsius relative to pre-industrial levels, which is the position of the Alliance of Small Island States.

[44][45] Prime minister Sopoaga said in his speech to the meeting of heads of state and government: Tuvalu’s future at current warming, is already bleak, any further temperature increase will spell the total demise of Tuvalu….

[46]Enele Sopoaga described the important outcomes of COP21 as including the stand-alone provision for assistance to small island states and some of the least developed countries for loss and damage resulting from climate change and the ambition of limiting temperature rise to 1.5 degrees by the end of the century.