UK defence committee warns on AUKUS commitment, calls for renewed impetus

AUKUS Pillar 1 is planned to deliver new SSN-AUKUS submarines to both the Royal Navy and the Royal Australian Navy. (BAE Systems)

The trilateral AUKUS defence and security pact could be put at risk by faltering UK government commitment and a lack of investment in key infrastructure, a report by the cross-party House of Commons Defence Committee (HCDC) has warned.

Publishing its report on 28 April 2026, the HCDC said the scale and ambition of AUKUS demanded “visible political leadership from the Prime Minister to counter the political drift that could see it derailed,” adding: “Failure to meet our AUKUS commitments would have severe implications both for the UK's defence and security, and for the UK's standing with its trilateral partners.

“With progress in some areas having already fallen short, the Government must do more—and do it faster—if it is to avoid those consequences and deliver on the promise that this seminal partnership affords.”

AUKUS - a trilateral defence and security partnership between Australia, the UK, and the US, was announced by the three governments in September 2021 and is split into two distinct components. The first part, known as Pillar 1, will see Australia acquire a sovereign fleet of nuclear-powered, conventionally-armed submarines (SSNs) with the support of the US and UK. This new submarine class – known as SSN-AUKUS – is planned to enter service with the Royal Australian Navy in the early 2040s. It is planned that they will start to replace the UK Royal Navy's (RN's) existing Astute-class SSNs from the late 2030s.

Pillar 2 covers the development of a range of advanced military technologies - including hypersonics, cyber, AI and electronic warfare - alongside increased defence co-operation.