四艘「繼承者」（Successor）級新一代核潛艇將攜帶三叉戟導彈，在Barrow-in-Furness 的BAE系統公司船廠建造。BAE系統表示，這四艘核潛艇將於2030年建成並開始服役，設計壽命至少30年。

The Successor-class is a proposed replacement for the Vanguard-class of ballistic missile submarines which entered service in the United Kingdom in the 1990s with an intended service life of 25 years.^] They will carry Trident D-5 missiles – the vehicle for delivering the UK's nuclear weapons.^[ Replacing the Vanguard submarines is claimed to be necessary if the Royal Navy is to maintain a "continuous at-sea deterrent" (CASD), the principle of operation behind the Trident system^]

In May 2011 the government approved the initial assessment phase for the new submarines and authorised the purchase of long lead-time items including steel for the hulls. In May 2015 the Conservative Party won the UK General Election on a manifesto which included a commitment to maintaining a CASD with four Successor submarines.^[4] The final decision to commit to the Successor programme was voted through on the 18th of July 2016, the Commons voted to renew Trident by 472 votes to 117 . ^[5] Construction is expected to start in late 2016 at the Barrow-in-Furness shipyard operated by BAE Systems Maritime – Submarines. The first submarine was originally expected to enter service in 2028.

Successor has generated controversy because of its cost and also as some political parties and campaign groups such as the Campaign for Nuclear Disarmament (CND) or Trident Ploughshares oppose the retention of CASD or any nuclear weapons by the UK on moral or financial grounds.