Christine O'Neill: Setting fixed terms for Westminster not as simple as it seems

ON THE face of it, the new government's proposal for fixed-term parliaments might be seen as Westminster simply following the lead of its younger Holyrood cousin.

Under devolution, we are now used to inflexible parliamentary terms and elections, like clockwork, held on the first Thursday in May every four years.

However, imposing that sort of routine on the UK parliament may be less straightforward than it seems. That is particularly so given the proposed "double lock" that would require a 55 per cent majority of MPs to vote in favour of an early dissolution.

Leaving aside the benefits to the electorate of having certainty about the timing of elections, a fixed-term parliament sustained by the "55 per cent rule" would have benefits for both sides of the coalition.

For the larger – but not quite majority – Conservatives, raising the bar for a dissolution vote to 55 per cent gives protection against the risk of an early election forced by a breakdown of the coalition.

For the Liberal Democrat partners, there is the reassurance of an apparent commitment by the Prime Minister to surrender what has, until now, been a highly-valued prerogative of his office: the right to ask the Queen for a dissolution of parliament when he chooses.

The Scotland Act contains very similar protections for the devolved Scottish Government. These were included deliberately by those who drafted the devolution settlement – recognising the instability that could face a Scottish Parliament elected by proportional representation and which would rarely, if ever, produce an overall majority.

So, for example, the Presiding Officer must request a dissolution where the Scottish Parliament votes in favour: but only where that vote is carried by a two-thirds majority of all 129 MSPs. Similarly, Scotland's first minister has no unilateral power to request a dissolution: at "best" he may resign as first minister, thereby triggering a statutory period of 28 days within which a new first minister can be chosen. Only if that process fails, will an election be called. Given this precedent, why not adopt similar rules for the UK parliament?

There are, of course, political objections. Some argue fixed-term parliaments and qualified majorities are acceptable only in the context of wider electoral reform and the introduction of a comprehensive system of proportional representation.

Others contend that first-past-the-post and a parliamentary system based on simple majorities remains the most legitimate way of electing and maintaining UK governments.

Quite apart from the politics, though, there are legal and constitutional questions thrown up by this proposal.

The first concerns the act of parliament that would impose fixed terms and the 55 per cent rule. The coalition agreement commits the government to putting a motion before parliament, to be followed by legislation. One obvious retort is such an act could have no practical value. If it could be repealed by 50.1 per cent of MPs – and given that repealing legislation could, with a fair wind, be introduced and passed on a single afternoon – this new act would not in reality present any greater obstacle to bringing down a government than exists at present.

What, though, if there is an attempt to "entrench" these new rules? The government's bill might, for example, provide that it cannot itself be repealed without a qualified majority of 55 per cent (or 65 per cent or 75 per cent) of all MPs in favour.

Such an attempt at entrenchment would mark a more fundamental departure for the UK parliament and would revive esoteric debates about parliamentary sovereignty that don't normally make it to prime-time TV. At their heart is this question: if sovereignty means the Westminster parliament can make or unmake any law it chooses whenever it chooses, can this 2010 parliament really limit how future parliaments could change the electoral system by raising the bar for its repeal? The answer, as one might expect from an esoteric debate, is "perhaps".

There are those who point to occasions on which parliament has altered the rules for making new laws (for example using the Parliament Acts to prevent the House of Lords from persistently blocking legislation) to support the view that sovereignty does allow for limitations on the "manner and form" of legislation. Others argue that even these limitations can be repealed by a simple majority of MPs and are not entrenched in any true sense.

To the disappointment, no doubt, of some it is unlikely that the courts would ever be asked to rule on the power of parliament to repeal, by simple majority, an act that, on its face, demands more.

Nevertheless, that the issue might arise suggests a bill to put in place fixed-term parliaments may be a little longer in production than first thought.

• Christine O'Neill is head of public law and parliamentary at Brodies LLP