The lack of clarity about how the next prime minister should be chosen may be just the start of the post-election constitutional headaches, writes Elliot Bulmer. However, he argues, Westminster could learn a trick from Holyrood is this area.

Before Blair came to power, the British system of government had a certain simplicity to it. Beneath its gothic façade, its internal logic of executive dominance was clear. The system was centralized, exclusionary and unrepresentative, but at least it seemed to provide a clear choice between the Government and Opposition, coupled with firm but responsible leadership.

Devolution changed all that. Although meaningful reform at the centre was excluded, the periphery was transformed. Not only were alternative centres of democratic power established, but proportional electoral systems were also adopted for devolved and European elections, enabling smaller parties to establish a toe-hold on power. By 2010, seven parties were in government across the UK;[1] in 2014, UKIP was the plurality winner of the European Parliament election. We now live in a reality of multi-level, multi-party politics.

This has strained what used to be quaintly named the ‘British Constitution’ – that ragged assortment of laws, conventions and traditions that described how we were governed. The rules were never binding, never precise, and never clearly stated in a way that would let citizens understand the distribution of power, but at least there was a consensus amongst the political elite about how these unwritten rules were supposed to work. That consensus has broken down. The absence of a written constitution has always meant that we have little protection against the abuses of power, but now even the proper uses of power are disputed. Nothing in the past three centuries of conventional adaptation has prepared us for such an alteration in the political landscape.

This fraying of the unwritten system is seen most clearly with regard to the process of government formation at Westminster. As long as there were only two significant parties, the royal invitation to form a government went to the leader of the majority. Now the situation is more complex and the risks of a crisis are greater.

In an attempt to provide order where there was none, Gordon Brown hurriedly produced a ‘Cabinet Manual’ before the 2010 election, which purported to be an authoritative statement of constitutional conventions. This was compiled by government insiders, without public debate; unlike a Constitution, it has no legal force and little legitimacy. The Manual’s insistence, for example, that the incumbent should have the first opportunity to form a government did not prevent the largest party from taking the initiative in 2010. Labour, which insisted on the primacy of the incumbent in 2010, is now insisting on the primacy of the largest party. This legitimacy-eroding uncertainty is what happens when the rules by which a country is governed are not clearly expressed and democratically endorsed.

It does not have to be so. In many countries across Europe and throughout the Commonwealth this problem has been solved through simple and universally accepted constitutional rules. In Ireland, for example, the Prime Minister is chosen by a formal vote of the chamber. These provisions remove the Head of State from the government formation process altogether. A similar provision was adopted in Scotland for the First Minister. If such a system were adopted at Westminster, Cameron and Miliband would stand for election on the floor of the House of Commons and it would be up to them to court the votes of other parties in order to become Prime Minister.

The UK’s constitutional troubles go beyond government formation. A century of unfinished business has left us with a ramshackle structure that increasingly difficult to defend. Only a thorough-going constitutional refoundation, embracing electoral reform, federalism, the second chamber, direct democracy, human rights, the restriction of prerogative powers, public ethics, and the establishment of a written constitution, can provide an adequate solution.

In the meantime, however, a simple Act providing for the election of the Prime Minister by the House of Commons, along Scottish lines, would at least provide a minimal adaptation to circumstances, and prevent much avoidable uncertainty.