With three days to go the general election the polls haven’t moved in weeks. The major parties are neck and neck on about 33% of the vote each, with the other 33% being shared between the Lib Dems, Ukip, the SNP and the other smaller parties. It’s going to be close and it could go either the Tories’ or Labour’s way. I have no idea who’s going to win, and I make no prediction. But, for the sake of argument, let us suppose that the result is something like this: Conservatives 290 seats; Labour 270; SNP 45; Lib Dem 25; Others 20.

If this were the result, the Conservatives and LDs could between them command 315 seats. Still a handful shy of a working majority. Add the DUP to the mix and you get to about 324: just enough once you discount the Speaker and the Sinn Fein MPs (who do not take their seats).

On the same result Labour plus the Lib Dems would command 295 seats. Add the SNP to the mix and that would rise to 340: a comfortable majority but one reliant on SNP votes.

On these figures neither a Conservative-led nor a Labour-led government will be secure. It is hard to see either lasting the five-year term until the next scheduled general election, in May 2020. A change of administration during the 2015-20 parliament, and/or an early general election before 2020, would seem more likely than not were the result this week to be close to the one set out here.

This post seeks to explain the constitutional rules that govern (1) the formation of a new administration in circumstances such as these and (2) the survival of that administration for the remainder of the five-year term. This involves analysis of two key documents: the Cabinet Manual and the Fixed-term Parliaments Act 2011. Neither existed at the time of the last general election, although the Cabinet Manual was in preparation then and one chapter of it had been published in draft. The Cabinet Manual is the civil service’s understanding of the key rules, conventions and practices of government (including government formation). It has no formal status in law but may be regarded as an authoritative statement. It is not legally binding, but a very good reason would be needed to depart from it, in my view. The Fixed-term Parliaments Act 2011 is an Act of Parliament. It is the law of the land, and remains as such unless and until a future Parliament amends or repeals it. To act contrary to it would be to act unlawfully.

The rules of government formation

First of all, it is important to bear in mind what we voters are doing at a general election. We are not electing a government. We are electing a House of Commons, out of which and from which a government will be formed. It may well be that most voters will cast their votes on the basis of who they want to be Prime Minister, but the truth is we are not electing the PM (unless you live in Witney or Doncaster North). We are electing representatives for our constituencies. Those representatives will collectively determine who holds office: that is their job as MPs, not ours as voters.

If a party wins an overall majority of seats in the House of Commons it is axiomatic that the leader of that party becomes Prime Minister and is invited by Her Majesty the Queen to form an administration. If Labour win more than 320 or so seats Mr Cameron will resign as Prime Minister with immediate effect and Mr Miliband will be in 10 Downing Street by mid-morning on 8 May. So much is straightforward.

But all the polls indicate that there will be a hung parliament: i.e. a House of Commons in which no one party has an overall majority of seats. The constitutional rule in these circumstances is that the leader who can command the confidence of the House forms a government. That confidence can be formally tested only when the House meets, but in 2010 this did not take place until 12 days after the general election had taken place. Thus, the government is usually formed before the House of Commons meets.

Government formation in these circumstances depends, first, on the parliamentary arithmetic (how many seats does each party have) and, secondly, on negotiations between the parties. Those negotiations are designed to see if some combination of parties can work together to propose a policy platform that would be likely to command a majority in the House. Working together can take a variety of forms, from formal coalition (as in 2010-15) via “confidence and supply agreements” to much more informal suck-it-and-see vote-by-vote deals. (A confidence and supply agreement is when a minor party agrees to support a major party in any motion of confidence and as regards the passing of its budget. Under such an arrangement there is no formal agreement on other matters of legislation or policy.

The incumbent Prime Minister may remain in office during the period of negotiations. He is under no duty to remain in office: no Prime Minister may be compelled to remain in office if he has concluded that he should properly depart. But, likewise, he is under no duty to resign. Gordon Brown did nothing wrong in not resigning until five days after the 2010 general election: he was perfectly entitled to remain in office during that time to see whether he could form an agreement with other parties. Mr Brown resigned as PM when it became clear to him that he could not do so and that Mr Cameron was better placed to try and form an administration.

On the other hand, an incumbent Prime Minister should not seek to cling to office once it has become clear that he is unlikely to be able to form an administration that can command the confidence of the House of Commons.

All three leaders of the major parties acted perfectly properly in 2010, the last time a hung parliament was elected.

From the above it can be seen that it is not true that the largest party gets to go first; still less that it has an automatic right to form a government. Earlier in the election campaign Scottish Labour made claims to this effect. They were wrong to do so. It is true that on every occasion since 1924 the largest party has (as a matter of fact) gone on to form a government, but there is no constitutional rule that this must be so. Indeed, the very first Labour government (of 1924) would have broken this rule! The constitutional rule is that the government must command the confidence of the House of Commons. In my scenario above, of Labour 270 + LD 25 + SNP 45 = 340, a Labour-led government could well command the confidence of the House, despite Labour being a smaller party than the Tories.

Would such a government be illegitimate, as some English voices on the centre-right have claimed in recent days? From a constitutional perspective the clear answer is No, it would not. Personally, I cannot see how SNP MPs could take office as ministers of the British Government when their core aim is to break Britain up by removing Scotland from the UK (how can you govern a place you want to break up?). But this is a personal view, not a constitutional rule and, in any case, neither the Labour party nor the SNP are proposing this sort of deal: were a minority Labour (or Lab/LD) government propped up by the SNP, we are told that this would be without the SNP playing a role in government (that is, it would be a suck-it-and-see, vote-by-vote arrangement, not a coalition). There is the world of difference between having separatist MPs in the House of Commons and having separatist ministers taking office in the British Government.

With all this in mind, what should happen if the result on Friday morning is something like the scenario I started with: Con 290, Lab 270, SNP 45, LD 25, Others 20? What should happen is that the Prime Minister remains in office and seeks support from other parties (presumably the LDs and the DUP) that would mean he could command the confidence of the House of Commons. Only if (or when) it became clear that such support would not be forthcoming should we expect him to resign.

The implications of the Fixed-term Parliaments Act 2011 (FTPA)

Before the FTPA was passed a parliament was elected for a maximum term (of five years) but it was for the Prime Minister to decide within that term when the next general election should be called. The Act removes this power from the PM. An early general election may occur now only if one of two things happens: either that the Commons passes a motion stating “that this House has no confidence in Her Majesty’s Government”; or that the Commons passes by a two-thirds majority a motion “that there shall be an early parliamentary general election”. The second motion is unlikely unless both Government and Opposition agree that an early general election is in their parties’ and the public interest.

A no confidence motion requires no two-thirds majority of MPs: as in any other parliamentary vote a bare majority of the votes cast is sufficient. The effect of a no confidence motion being passed is not that there will be an immediate general election. Rather, the Act stipulates that there will be a 14-day period for the parties (both governing and opposing) to seek to form a new administration that can command the confidence of the House. Only if no such administration is formed within this window will there then be a dissolution and a fresh election.

The FTPA breaks two matters that had previously been linked: confidence and supply, and resignation and dissolution. Let me explain each.

It had formerly been thought that were a government to be defeated on its Queen’s Speech (i.e. the outline of its legislative programme, presented to Parliament at the beginning of each session) or on its budget, such a defeat would amount to a loss of confidence and would lead to the government resigning and to a general election. Under the FTPA this is no longer the case. It is clear under the Act that only a motion using the words “that this House has no confidence in her Majesty’s Government” is a vote of confidence. No other vote, no matter how important, is a vote of confidence, unless it includes these words. Thus, were a government now to lose a vote on its Queen’s Speech, or were a government now to fail to get its budget through, this would not of itself mean that the House had lost confidence in the government.

This is why the SNP leadership considers that they can prop up a Labour-led government whilst, at the same time, defeating that government on its budget until it introduces a budget that accords with the SNP’s wishes. However, the SNP leadership is mistaken.

Their mistake lies in their having overlooked the distinction between resignation and dissolution. Under the FTPA the Prime Minister has lost his power to call an early general election: the PM can no longer directly control the timing of the dissolution of Parliament. But, as I noted above, no-one may compel a Prime Minister to remain in office. Suppose that a Labour-led minority government is struggling to pass its budget in the face of SNP resistance. There is nothing to stop Mr Miliband going to the House to say that, if his budget is not passed, he will resign on behalf of the government and advise the Queen that the Leader of the Opposition should be invited to form a government. If the PM does this the SNP would have to support Labour’s budget or usher in a new Tory government. That new Tory government may well not last long: if it could not gain the confidence of the House it could suffer defeat on a motion of confidence and we would be into the 14-day period provided for by the Fixed-term Parliaments Act. None the less, the FTPA does not give to a minority bloc of even 45 SNP MPs quite the strong hand that the SNP leadership imagines. For sure, the parliamentary arithmetic at the end of the week could allow the SNP to cause chaos and wreak havoc, but the Fixed-term Parliaments Act is not a legislative licence for the tail to wag the dog.

Further reading

Other commentaries on the formation and government and the Fixed-term Parliaments Act which I have found useful include Lord Norton’s article in (2015) Parliamentary Affairs and these blog-posts by Mark Elliott and Carl Gardner.