Despite Keir Starmer’s landslide majority just two years ago, the former Prime Minister announced his resignation from the premiership on 20 July. The departure of yet another prime minister, in short order, follows a series of political misjudgements that saw his support in both parliament and country drain away.

The only candidate to replace Mr Starmer was the former mayor of Manchester, Andy Burnham, who had recently been elected as MP for Makerfield in a constituency that voted strongly for the insurgent Reform party at the recent local elections.

Some political figures including Nigel Farage, the leader of Reform, suggested that if Mr Burnham became party leader and prime minister, he would be obliged to seek an early general election to secure his own democratic mandate.

Political pressure to do so was perhaps not diminished when evidence emerged (there is always a tweet) that Mr Burnham had himself made such a call when a previous prime minister was defenestrated.

We need to start demanding a General Election at the end of this Tory leadership election.

Would a refusal by Mr Burnham to heed these clarion calls be in some way unconstitutional or is he entitled to attempt to govern for the rest of this parliamentary term before going to the country? After all, Mr Burnham was not even an MP at the last election, let alone a cabinet rank member of the putative new government. How can someone not included in the executive slate at the last election now do a Bolingbroke in this way? The discomfort is genuine, but does not cross the line to unconstitutional, as this blog attempts to explain.

The orthodox view

The mutterings off-stage from Farage as to the need for an early general election were swiftly met by numerous commentators declaring that no such election is constitutionally required because the UK system only elects members of parliament to the legislature – representing their local constituencies – and not the government. Recent events would appear to bear out this claim, with none of the rapidly expanding list of historic or recent mid-term elevations to the top job feeling obliged to call an early election for the purpose of securing their own mandate. An excellent recent post on this blog by Dane Luo provides useful context and background.

The constitutional test for who should be prime minister would appear to bolster the commonly held view. The decision is formally made by the monarch under royal prerogative. That choice is heavily, and possibly entirely, circumscribed by a powerful convention that the King is obliged to appoint the person best placed to command a majority in the House of Commons. Nowadays, this is invariably the leader of the party or coalition with such a majority, with various ancillary rules governing situations where no such majority exists.

The democratic mandate is more nuanced nowadays

If the prime minister’s mandate derives solely from parliament, what then is the source of the evident unease clearly felt by newly minted incumbents to the office? John Griffith provides the infamous answer, which is that in the United Kingdom the constitution is what happens – and the meaning of what happens in elections has changed. That change is now reflected in practice, convention and law.

The view of the purpose and effect of general elections as not conferring any executive mandate (to the extent that it is or has been held) is not just inadequate, it is politically, constitutionally, even legally, wrong. The settled modern constitutional reality is that we do not vote just for the legislature at general elections. Our votes are bifurcated. We vote for the legislature, and we vote for the executive.

This can be seen by the fact that party names and logos now appear on modern ballot papers, illustrating that the leadership of the parties, and their manifesto promises, are directly on the ballot. This fact is also evidenced in the operation of the Salisbury-Addison convention, which establishes that policy promises made by the executive slate expressed in the party manifesto are given extra weight in the House of Lords. There is also a little known statutory requirement (Rule 63) for a fresh byelection if a candidate for a registered party in a particular constituency dies during the general election but not if the candidate is independent.

The bifurcated nature of the individual vote is therefore recognised in law. The right of registered parties to have their name and emblem, and therefore their policies and leadership, put to the electorate in a particular constituency is a statutory requirement. The substance of what is voted on is of course the party manifesto and executive slate for whom the manifesto constitutes a statement of political principles and intended programme, albeit containing commitments that themselves have no legal force.

Our vote at a general election thus confers two democratic mandates. First, it confers a mandate on the executive slate standing for office on its manifesto, however loosely the contents are thereafter interpreted. Secondly, it confers a mandate on MPs representing their constituencies in their legislative capacity to pass laws, authorise supply, scrutinise the government and participate in the great debating chamber of the nation.

Constitutionally the government sustains its right to govern through time by retaining the confidence of the House of Commons, after its authority has been conferred by it winning the battle for seats. This right continues until and unless it loses a formal vote of no confidence or a general election is called.

In the event of vacancy, the requirement for the monarch to appoint the person ‘best placed’ to command the confidence of the House of Commons relies on the ongoing confidence of backbenchers, rather than the snapshot conferral of executive authority granted by the general election victory measured in seats.

Cabinet Government

Political discourse in the United Kingdom is somewhat different from the overwhelming focus on the executive seen in countries such as the United States where the domination of the airwaves by the President is very evident. Nevertheless, the prominence of the main candidates for prime minister at a general election is ever increasing. Cabinet members or their shadows do, however, get significant exposure and at the local and regional level, lively debates do take place as well.

Notwithstanding the changing media environment, then, it is still true to say that we live in a system of Cabinet Government rather than a presidential one. Indeed, more than one prime minister has been brought down by a loss of confidence on the part of senior ministers and others. This was seen when Mrs Thatcher was brought down, and again with Ms Truss. As Mr Johnson, another famous example, succinctly put it ‘when the herd moves, it moves’.

In such circumstances, it is unsurprising that the leading replacement candidates are almost invariably drawn from the same executive team that stood at the previous election. In a very real sense, therefore, a shuffling of the cabinet pack to determine a new primus inter pares can continue to rely on the executive mandate conferred on the team as a whole, however prominent the role of the prime minister during the campaign.

The mandate for new prime ministers thus retains its executive limb as well as its ongoing legislative limb by maintaining the confidence of the House. Despite these constitutional underpinnings, it can be no surprise that an incoming prime minister – as a matter of pure politics – is bound to feel that the executive mandate is perhaps less powerful than it seemed to their predecessor.

This is understandably a potentially uncomfortable experience for them until they do eventually seek a new mandate for themselves and their new Cabinet from the electorate through a fresh general election. Uncomfortable, but not unconstitutional.

These hard political realities perhaps go some way to explain why there are inevitable calls from politicians, media and members of the public for a new general election when a new prime minister is appointed. Those calls are based on sound constitutional instincts explained above and, whether they are successful or unsuccessful, the calls are reasonable and justified in law and in fact. Any constitutional theory that cannot, or point-blank refuses, to accommodate these political truths must be regarded as deficient to that extent.

In the end, though, the decision on the timing of an election is a matter for the prime minister’s discretion because they possess the right to advise the monarch on when to dissolve parliament, subject to the five-year statutory limit. Such decisions involve balancing quintessentially high policy and non-justiciable factors based on financial, strategic and other considerations. Whether they should call the election is a political choice.

The Burnham conundrum

As we have already noted, however, the peculiar conundrum for Mr Burnham is that in the 2024 election, he was not even an MP, never mind a shadow cabinet member. Tricky. He cannot personally rely on the mandate acquired by the executive slate that led Labour at the last election. Perhaps this is why he has been careful recently to express his endorsement of the 2024 Labour manifesto.

This puts Mr Burnham in a highly unusual and arguably weaker position, quite different to Major, Brown, May, Johnson, Truss and Sunak, because they all stood as part of the party leadership at the prior election to their elevation to the premiership. He can perhaps point to his existing executive mayoral responsibilities on a Labour ticket, and his prior leadership bids when he was an MP as well as his express adoption of the 2024 manifesto, but these are barely sufficient straw for the brick he is trying to make. It seems likely that his less-than-ideal mandate may be the subject of sustained pressure from opposition voices and others.

Conclusion

The scenario canvassed in this blog is downstream of possibly the most important constitutional principle in the United Kingdom constitution which is the doctrine of confidence. At general elections, the executive slate seeks the confidence of the people for their programme of government in their manifesto, conferred by being first past the post in terms of seats. MPs secure a legislative mandate at the same time. Our votes are bifurcated. Thereafter, the confidence of the people’s representatives in parliament must be maintained, failing which a fresh mandate must be secured at the ballot box.

This blog has argued that the strikingly unusual position of Mr Burnham in being elevated to the premiership without being a member of his party’s slate at the last election puts him in an uncomfortable position and one that may continue to draw comment both inside and outside the House of Commons.

The author would like to thank the UKCLA editors and Gavin Phillipson for their helpful comments on an early draft. The usual disclaimer applies.

Dr Robert Craig, Senior Lecturer, University of Bristol

(Suggested citation: R. Craig, ‘Uncomfortable, But Not Unconstitutional – The Transition to a New Prime Minister’, U.K. Const. L. Blog (3rd September 2026) (available at https://ukconstitutionallaw.org/))