Senior diplomatic appointments

How are senior diplomats appointed?

The UK has both high commissioners and ambassadors – the former representing the UK in Commonwealth countries and the latter as 'head of mission' in other countries. 

Both roles are appointed through royal prerogative. This means that they are formally appointed by the King but on the advice of the foreign secretary, or often the prime minister for more senior diplomatic postings. Almost all senior diplomatic roles are filled by career civil servants and many will go through a competitive process as with other senior civil service roles. But, unusually in the civil service, heads of diplomatic missions  are excepted from rules around appointment by merit on the basis of open competition so the foreign secretary or prime minister can recommend the appointment directly without a formal recruitment process. ⁹ https://www.legislation.gov.uk/ukpga/2010/25/section/10

When an individual is selected the foreign secretary then formally writes to the King recommending their appointment, who is then provided with an official diplomatic commission by the King and will meet with him. This is followed by letters of credence that are presented to the head of state in the country to which they are appointed. These vary, for instance on whether it is a Commonwealth country or not, or whether the host country is led by a monarch or president. Where the head of state is also the British monarch, letters of introduction to the prime minister are used instead. Letters of recall are also provided for the outgoing ambassador or high commissioner. ¹⁰ https://commonslibrary.parliament.uk/how-are-diplomats-appointed/   

Can ambassadors be political figures? 

Yes. Though today most are career diplomats, the appointment of political figures to UK ambassadorial roles is not new. Before the development of the modern civil service, ambassadors would often be political or even military figures. The Duke of Wellington was ambassador to France from 1814 to 1815, having commanded British forces during the Napoleonic wars. He later became prime minister. 

By the early 20th century, senior diplomats were increasingly likely to come from the career diplomatic service in the Foreign Office. But political appointments continued occasionally, particularly to the role of ambassador to the US. In 1961 the Conservative politician David Ormsby-Gore was appointed by Harold Macmillan to the US Embassy. A decade later James Callaghan controversially appointed his own son-in-law Peter Jay, a journalist, to the same role in 1977. 

Lord Llewellyn, former chief-of-staff to David Cameron, was appointed as ambassador to France in 2016.  While considered a political figure, Llewellyn had diplomatic experience having previously served as a civil service aide to Chris Patten while he was governor of Hong Kong and later as European commissioner. He was also chief-of-staff to Paddy Ashdown while he was high representative for Bosnia and Herzegovina. He subsequently became ambassador to Italy in 2022 and in August 2025 it was reported he was being appointed as political director at the FCDO. ¹² https://www.ft.com/content/d1d94155-d12b-4dc4-a208-e3b21ed63112  And until recently senior Labour figure Peter Mandelson was Keir Starmer’s ambassador to the US.

Are ambassadors vetted? 

Yes. Anyone talking up an ambassadorial role will need security vetting. Career diplomats will already have security clearance, however, and even a political appointee will have had vetting if they were previously a special adviser or minister.

Many, if not all, ambassadorial posts will require 'developed vetting' – one of the highest forms of government security clearance. This involves the same checks as lower levels of vetting (such as criminal record and other checks), but also detailed interviews and disclosures about an individual’s personal life and past. The onus is on the individual undergoing vetting to disclose relevant information. 

For such senior roles, as with other appointments like ministers, there is a separate judgement for the prime minister to make around whether the individual is an appropriate figure to hold the role – whether, for example, past comments or actions could embarrass the government in the future. To help with this, while No.10 is considering candidates they may ask officials to conduct some due diligence; this usually involves reviewing publicly available information and is done prior to full security vetting.

How are ambassadors removed from their posts?

An ambassador can be withdrawn with immediate effect. On 11 September 2025, following the release of emails detailing then ambassador to the US Peter Mandelson’s friendship with convicted paedophile Jeffrey Epstein, the prime minister asked the foreign secretary to withdraw Mandelson from the role.  

Ambassadors might also be withdrawn from the host country if they became persona non grata, or if their home country is sending a significant diplomatic signal. Ambassadors can also resign. In 2019 the then ambassador to the US Kim Darroch resigned after the leak of sensitive communications between him and the Foreign Office revealed a letter where he referred to the Trump administration as “inept” and “dysfunctional”.