The deputy prime minister and first secretary of state

Who is the deputy prime minister?

Unlike the US vice president, there is no constitutional deputy who automatically deputises for the prime minister or who would take over in the event the prime minister was incapacitated.

However, British prime ministers have sometimes chosen to ask another minister to act as their informal deputy. This de facto deputy has sometimes been given the honorific title ‘deputy prime minister’ but at other times has been the first secretary of state or the chancellor of the Duchy of Lancaster.

David Lammy was appointed deputy prime minister on 5 September 2025 following his predecessor Angela Rayner’s resignation. Lammy is also the Lord Chancellor and the secretary of state for justice. 

Deputy prime ministers have tended to play a more substantial role in Labour governments because the deputy Labour party leader is elected by party members and so has their own power base. However, the role of deputy prime minister and deputy Labour party leader are not necessarily always held by the same individual. The deputy prime minister is appointed by the prime minister whereas the Labour party deputy leader is elected by party members. Lucy Powell, the MP for Manchester Central, is the current Labour party deputy leader after being elected in October 2025. 
 

What is the difference between deputy prime minister and first secretary of state?

The title of first secretary of state is used to indicate that the holder ranks below the prime minister but is more senior than other secretaries of state. It confers no automatic rights or responsibilities but can, though not always, coincide with a role deputising for the prime minister. As the most senior secretary of state, the first secretary will sit closest to the prime minister around the cabinet table.

There can also be a second or third secretary of state, but usually this informal rank is inferred from their position in the cabinet hierarchy rather than a title provided to them.

The title of deputy prime minister similarly confers no automatic rights and responsibilities. It is usually used either to give a title to the leader of the second party in a coalition government or to convey a seniority above the first secretary of state, either because a prime minister wishes to empower a particular minister or, more usually, because a particular minister has insisted on the title. The deputy prime minister may actually deputise for the prime minister – at PMQs, on cabinet committees or elsewhere – but this is not guaranteed. 

Nick Clegg described how the practicalities and dynamic of the 2010-15 coalition government shaped his role as deputy prime minister: 

“I know the title was the same, but my role [as deputy prime minister] bore absolutely no relationship to John Prescott or Michael Heseltine… The Coalition Government couldn’t do anything unless both sides agreed. So we had to set up from scratch something which Whitehall has never done before, and certainly has not done since, which is create a sort of two-headed, bicephalous way of making decisions.”

Who is the chief secretary to the prime minister?

In September 2025, Keir Starmer also appointed another senior deputy, Darren Jones, as chief secretary to the prime minister, a new role. Jones was also appointed later that same week to chancellor of the Duchy of Lancaster in the Cabinet Office.

The chief secretary role is intended to oversee and support the delivery of the prime minister’s priorities across government. In that sense, the role looks similar to that of a first secretary of state. The chief secretary attends cabinet meetings and reports directly to the prime minister.

However, the government has never had a chief secretary to the prime minister before and so the exact responsibilities of the role in practice will become clearer with time. 

How do ministers deputise for the prime minister?

There are a number of occasions on which the prime minister might wish to delegate some of their responsibilities.

Prime ministers have often asked deputy prime ministers or first secretaries of state to chair cabinet committees in their place. John Prescott chaired nine cabinet committees in 2006 ¹⁸ House of Commons Library, The office of Deputy Prime Minister, 2 July 2013, https://researchbriefings.files.parliament.uk/documents/SN04023/SN04023.pdf  while Thérèse Coffey chaired two during her brief tenure as deputy prime minister in 2022. ¹⁹ GOV.UK, List of Cabinet Committees and their membership, 23 September 2022, https://webarchive.nationalarchives.gov.uk/ukgwa/20221101061939/https://www.gov.uk/government/publications/the-cabinet-committees-system-and-list-of-…  Currently, Darren Jones chairs four cabinet committees as chief secretary and chancellor of the Duchy of Lancaster.

The deputy prime minister is often called upon to stand in at PMQs when the prime minister is away, although this responsibility can also fall to another senior minister. Dominic Raab frequently stood in for Boris Johnson and Rishi Sunak, first in his capacity as first secretary of state and then as deputy prime minister. As chancellor of the Duchy of Lancaster, David Lidington frequently stood in for Theresa May, who never officially designated a deputy prime minister. David Lammy deputised for Keir Starmer at PMQs for the first time in November 2025 while the prime minister was attending a climate conference in Brazil. 

At other times, prime ministers have asked a close ally to act as a de facto deputy or ‘fixer’ and delegated aspects of their responsibilities to them. This might include chasing progress on key policies and, particularly, cross-cutting issues, brokering deals between departments and chairing meetings and committees. In recent years this role has been given to a minister based in the Cabinet Office, and therefore benefitting from the resources of the Cabinet Office and proximity to No.10. Oliver Dowden was said to play such a role for Rishi Sunak.

When the prime minister is on holiday, a senior minister is appointed to deal with day-to-day prime ministerial business. This is likely to be the deputy prime minister where there is a minister with that title, but it does not have to be.

Finally, when a prime minister is ill or incapacitated, another cabinet minister would usually be expected to take on some of the PM’s responsibilities. Unlike the US, however, there are no formal rules that govern this handover of power. In 2020, when then-prime minister Boris Johnson went into intensive care while suffering from Covid-19, it was then-first secretary of state Dominic Raab who took on his day-to-day responsibilities. ²⁰ Barnes P, ‘Coronavirus: Who’s in charge if the PM is ill?’, BBC News, 15 April 2020, www.bbc.co.uk/news/uk-politics-52193461

If a prime minister died in office, would the deputy prime minister take over?

Not necessarily. The UK has no automatic process for what happens if a prime minister dies or is incapacitated in office, although there are certain constitutional principles that would be followed. After Boris Johnson was hospitalised in 2020, the Cabinet Office considered what would be recommended practice in future, but this still does not amount to a constitutional rule.

The central constitutional principle is that a prime minister must be appointed by the monarch on the basis of commanding the confidence of parliament. There is no constitutional provision for an ‘acting prime minister’. The UK is formally governed by the cabinet who either exercise statutory and some prerogative powers in their own right, or who advise the monarch on how to exercise other executive powers. If the prime minister is incapacitated temporarily then the cabinet can advise the monarch in the absence of the prime minister.

A prime minister remains in post until they resign or otherwise vacate the role. In these circumstances, if the party in government had a majority in parliament then the requirement to command confidence would mean that the governing party would have to select a candidate with the support of its MPs. In practice, given that cabinet ministers are already acting as the monarch’s principal advisers, a replacement would likely be chosen by and from the existing cabinet, at least until a new leader of the party could be elected. This may be the PM’s deputy, but this is not guaranteed. ²² Haddon C, ‘The UK now needs a formal acting prime minister role’, Institute for Government, 7 April 2020, www.instituteforgovernment.org.uk/article/comment/uk-now-needs-formal-acting-prime-minister-role; Saunders R, ‘What Happens If A Prime Minister Dies in Office?’, Mile End Institute, 6 May 2020, www.qmul.ac.uk/mei/news-and-opinion/items/what-happens-if-a-prime-minister-dies-in-office-dr-robert-saunders.html

Is there always a deputy prime minister?

There is not always a deputy prime minister. In fact, the concept of a deputy prime minister is relatively new. Clement Attlee was the first deputy prime minister, serving during the wartime coalition from 1940–45. Between then and 2010, eight ministers deputised for the prime minister, but there were long periods without any deputy. ²⁵ House of Commons Library, The office of Deputy Prime Minister, 2 July 2013, https://researchbriefings.files.parliament.uk/documents/SN04023/SN04023.pdf

Since Nick Clegg’s appointment as deputy prime minister during the coalition, use of the title has become more common. There have been five deputy prime ministers and three first secretaries since 2015. This excludes Philip Hammond who was briefly and mistakenly appointed to the role in 2016. ²⁶ Zeffman H and Coates S, ‘Hammond promoted to PM’s deputy by mistake’, The Times, 29 October 2016, www.thetimes.co.uk/article/hammond-promoted-to-pm-s-deputy-by-mistake-v2d978vqb   There were two periods between 2015 and 2019 where there was no appointed deputy prime minister or first secretary, although the chancellor of the Duchy of Lancaster performed a similar role for some of that period.

Sometimes there is both a deputy prime minister and a first secretary of state in one government. During the 2010–15 coalition government, Nick Clegg was deputy PM and William Hague as first secretary of state. Clegg’s title reflected his role as the leader of the junior coalition party and Hague’s title his status as a party ally of the prime minister. Currently, there is both a deputy prime minister and a chief secretary to the prime minister. 

Is there a department of the deputy prime minister?

The title of deputy prime minister or first secretary of state has usually been held by someone with another cabinet role and they have performed their role from an existing department.

Between 2010 and 2015, Clegg operated as deputy prime minister from the Cabinet Office and was provided with a larger team to support his responsibilities. He was also Lord President of the Council, a separate title that gave him responsibility for the privy council.

Some deputy prime ministers have had a team within the Cabinet Office alongside another departmental office. Between 2001 and 2006, John Prescott was supported by an Office of the Deputy Prime Minister, holding responsibility for the Social Exclusion Unit and Regional Coordination Unit, alongside his responsibilities in the Department for the Environment, Transport and the Regions. ²⁸ House of Commons Library, The office of Deputy Prime Minister, 2 July 2013, https://researchbriefings.files.parliament.uk/documents/SN04023/SN04023.pdf

How important is the role?

This depends on the circumstances of government. During the coalition, the deputy prime minister was unusually powerful because Nick Clegg was the most senior representative of the Liberal Democrats in government. His position was written into the coalition agreement, and some responsibilities were transferred from the secretary of state for justice to the deputy PM to increase his powers. 

Outside of coalition, the relative strength of the deputy prime minister or first secretary of state depends on their relationship with the prime minister. As first secretaries of state Lord Mandelson and Damian Green were, in particular, known for acting as fixers for the prime minister, as was David Lidington as Theresa May’s chancellor of the Duchy of Lancaster. Other prime ministers have relied on their chancellor as a second in command.

Lord Heseltine, who served as John Major’s deputy prime minister between 1995 and 1997, told our Ministers Reflect archive how closely he worked with the prime minister in the role:

“You can be many things as Deputy Prime Minister. You can first of all be the king over the water, the heir apparent. I did not take that view. I took the view that I was inseparable from John Major and there would not be a sliver of cigarette paper between us.”