Leader of the Unionist Party

Leader of the Unionist Party
Incumbent The Marquess of Dorchester since 27 March 2025
Type	Party leader
Status	Chief executive officer
Inaugural holder	The Marquess of Dorchester
Formation	1 May 2024

The Leader of the Unionist Party is the highest position in the Unionist Party. The current holder of the position is Thomas Carew, The Marquess of Dorchester, who assumed the position on 27 March 2025.

From the party's formation until 27 May 2024, there was no formal process for electing a Leader and its inaugural holder, Lord Sidmouth, held the role de facto without contest, with the agreement of the Unionist Frontbench. Following the adoption of the Party Charter during the Unionist's first conference in Brighton, Josephine Carew-Grey, 1st Baroness Wilton was the first Leader to be elected, though she ran unopposed. She assumed the role on 27 June 2024.

When the Unionist Party is the leading parliamentary group in the House of Commons, the Leader of the Party serves as the Prime Minister of Great Britain and First Lord of the Treasury, as well as being responsible for giving binding advice to the Sovereign for the appointment of Ministers of the Crown. Concordantly, when the party is in opposition, the party leader serves as the Leader of the Opposition and Lord Treasurer-Depute, chairing the Shadow Cabinet.

As of July 2025, Josephine Carew was the first and only woman elected party leader.

Four individuals have held the position, two of whom have done so over two seperate tenures. Currently, Thomas Carew, The Marquess of Dorchester is the longest serving Leader overall.

Selection Process

According to Section 1.3.1 of the Unionist Party Charter, the Party Leader is elected from amongst a list of Prospective Candidates, with the election run by the Chair of the Party.

Leaders of the Unionist Party

Portrait	Leader	Constituency	Took office	Left office	Government
					Party		Prime Minister	Term
	The Viscount Sidmouth	East Devon	1 May 2024 (Founder)	27 June 2024 (58 days)		Unionist Party	Himself	Knightstone Premiership
	The Baroness Wilton	Tavistock	27 June 2024 (Elected)	2 August 2024 (37 days)			Herself	Wilton Premiership
	The Duke of Warwick	York Central	2 August 2024 (Elected)	4 October 2024 (64 days)			Himself	Warwick Premiership
							Lord Sidmouth	First Sidmouth Premiership
	The Baron Calder	County Clare	4 October 2024 (Elected)	9 February 2025 (129 days)			Himself	Calder Premiership
							The Duke of Somerset	Third Somerset Premiership
							Lord Sidmouth	Second Sidmouth Premiership
							The Duke of Cambridge	Cambridge Premiership
	The Countess of Strathmore	East Devon	9 February 2025 (Elected)	26 March 2025 (46 days)			The Duke of Cambridge	Cambridge Premiership
							Herself	Strathmore Premiership
							Lord Kirkwall	Kirkwall Premiership
	The Marquess of Dorchester		27 March 2025 (Elected)	Present (128 days)			Lord Kirkwall	Kirkwall Premiership
							The Duke of Warwick	Second Warwick Premiership
							Himself	Dorchester Premiership

Elections of Unionist Leaders

Date	Leader Elected	Location	Chair	Proposer	Seconder
28 May 2024	Lady Knightstone	Grand Brighton Hotel (Party Conference)	Lady Knightstone	The Baron Knightstone	August Carew-Grey
1 August 2024	The Duke of Warwick	Grand Brighton Hotel (Party Conference)	The Baron Calder	The Baroness Wilton	The Baron Calder
29 September 2024	The Baron Calder	NEC Birmingham (Party Conference)	The Baron Calder	The Duke of Warwick	The Viscount Sidmouth
			The Viscount Sidmouth
9 February 2025	The Countess of Strathmore	Grand Hotel, Eastbourne (Party Conference)	The Earl of Devon	The Earl of Devon	The Viscount Clare
27 March 2025	The Earl of Devon	Grand Hotel, Eastbourne (Party Conference)	The Earl of Devon	The Viscount Clare	Lady Hereford
21 July 2025	The Baron St Brides	Grand Hotel, Eastbourne (Party Conference)	Lady Hereford	Marchioness of Dorchester
			The Marquess of Dorchester