Editing Vanguard-class submarine (section)

===Replacement===
{{Main|Dreadnought-class submarine}}

The Vanguard class had an originally intended service life of 25 years.<ref>{{Cite web |last=Service |first=Nuclear Information |date=2023-08-07 |title=HMS Vanguard leaves Devonport after 7 years of maintenance |url=https://www.nuclearinfo.org/article/hms-vanguard-leaves-devonport-after-7-years-of-maintenance/ |access-date=2024-05-28 |website=Nuclear Information Service |language=en-GB}}</ref> This would put the retirement dates for the class at 2018, 2020, 2021, 2024.<!-- Feel free to move this bit somewhere better in the article, but I feel this should at least be mentioned somewhere on this page. -->

On 4 December 2006, then Prime Minister [[Tony Blair]] revealed plans to spend up to £20&nbsp;billion on a new generation of ballistic missile submarines to replace the ''Vanguard'' class. In order to reduce costs and show Britain's commitment to the [[Treaty on the Non-Proliferation of Nuclear Weapons|Non-Proliferation Treaty]], Blair suggested that submarine numbers could be cut from four to three, while the number of nuclear warheads would be cut by 20% to 160.<ref name="WhitePaper">{{citation |url=http://www.mod.uk/NR/rdonlyres/AC00DD79-76D6-4FE3-91A1-6A56B03C092F/0/DefenceWhitePaper2006_Cm6994.pdf|title= The Future of the United Kingdom's Nuclear Deterrent|date=4 December 2006|publisher=[[Ministry of Defence (United Kingdom)|Ministry of Defence]] | access-date =5 December 2006}}</ref> On 23 September 2009, then Prime Minister [[Gordon Brown]] confirmed that this [[Rule of thirds (military)|reduction to three]] submarines was still under consideration.<ref>{{cite news| url=http://news.bbc.co.uk/1/hi/uk_politics/8270092.stm| author=BBC News| title=Brown move to cut UK nuclear subs | access-date=23 September 2009 | date=23 September 2009}}</ref> In February 2011, the [[Secretary of State for Defence|Defence Secretary]] [[Liam Fox]] stated that four submarines would be needed if the UK was to retain a credible nuclear deterrent.<ref>{{cite news| url=https://www.bbc.co.uk/news/uk-scotland-12504517 |work=BBC News  | title=Trident nuclear fleet cuts ruled out by Liam Fox | date=23 February 2011}}</ref> On 18 May 2011 the British government approved the initial assessment phase for the construction of a new class of four submarines, paving the way for the ordering of the first long-lead items and preparations for the main build to begin in the future. This new class of submarine, now known as the [[Dreadnought-class submarine|''Dreadnought'' class]], will retain the current Trident II missiles, and will incorporate a new [[Rolls-Royce PWR#PWR3|'PWR3']] nuclear reactor as well as technology developed for the {{sclass|Astute|submarine|0}} nuclear-powered fleet submarines of the Royal Navy.

A vote on the Trident renewal programme was held in the [[House of Commons of the United Kingdom|House of Commons]] on 18 July 2016, and determined that the UK should proceed with construction of the next generation of submarines. The motion passed with a significant majority of 472 MPs voting in favour and 117 against. The MoD put the cost of building, testing and commissioning the replacement vessels at £31&nbsp;billion (plus a contingency fund of £10&nbsp;billion) over 35 years, or about 0.2&nbsp;per&nbsp;cent of government spending, or 6&nbsp;per&nbsp;cent of defence spending, every year.<ref name="modfeb16">{{cite web|url=https://www.gov.uk/government/publications/uk-nuclear-deterrence-factsheet/uk-nuclear-deterrence-what-you-need-to-know|title=UK nuclear deterrence: what you need to know|publisher=Ministry of Defence|date=26 February 2016|access-date=1 March 2016}}</ref> It is expected the new fleet of submarines will come into operation starting 2028 at the earliest<ref name="auto"/> and certainly by the 2030s.<ref>{{cite news|url=https://www.bbc.co.uk/news/uk-politics-36830923|title=MPs approve Trident renewal|date=18 July 2016|work=BBC News|access-date=18 July 2016|quote=MPs approve Trident renewal|author=<!--Staff writer(s); no by-line.-->}}</ref> The ''Dreadnought'' class will extend the life of the Trident programme until at least the 2060s.<ref>{{cite news|url=https://www.independent.co.uk/news/theresa-may-trident-renewal-nuclear-attack-threat-labour-free-vote-a7141826.html |archive-url=https://ghostarchive.org/archive/20220811/https://www.independent.co.uk/news/theresa-may-trident-renewal-nuclear-attack-threat-labour-free-vote-a7141826.html |archive-date=11 August 2022 |url-access=subscription |url-status=live|title=Theresa May warns threat of nuclear attack has increased ahead of Trident vote|author=Tom Peck|date=18 July 2016|access-date=18 July 2016|work=Independent}}</ref>