ONE OF THE few certainties about the independence campaign is that there will be further constitutional change. ‘Better Together’ and the UK government have both conceded that, if a referendum on independence is won by the unionist camp, further powers will be devolved to Holyrood.

In many ways this is regrettable. It will require the fourth great national debate on the constitution in Scotland since 1992, meaning that Scottish politics will have been dominated by constitutional matters for a quarter of a century. I have written before how this obsession damages the country, not just by sucking energy away from real policy making, but by forever twisting politics to fit the constitutional agenda of the various parties.

But the ‘line in the sand’ declared by Tories and Labour after the Calman Commission has already been breached. It remains to be seen how the unionists will finesse the question of more powers. They obviously want to avoid a ‘second question’ in the independence referendum itself. At the moment they seem to be winning the argument on this point, but they will have to come up with a convincing alternative, perhaps promising some sort of post-referendum ‘national convention’.

In effect, therefore, Calman will be repeated, and a similar sort of compromise reached, satisfying neither the ‘devo-max’ brigade nor those who fear that devolving more powers will destabilise the union.

Actually, the exact settlement doesn’t really matter except in that it must be durable. Holyrood already possesses enough powers to last a lifetime of radical government, and devolving more won’t make much difference. There are plenty of examples of workable federal systems around the world, any one of which could suit Scotland.

The real problem is not the extent of Holyrood’s powers, but the fact that we spend the whole time arguing about them. We need to find a solution that will stand the test of time.

I do not want here to argue the toss about which portfolio of tax powers will provide the most stable package for the next iteration of devolution to stick. Instead I want to address another aspect of the devolved settlement, which is the timing and nature of Holyrood elections.

Elections to the Scottish parliament have always been coloured both by the constitutional debate and by events elsewhere in the UK. Both influences are unhealthy. I have already mentioned the problem of our constitutional obsession. But the UK dimension is just as distracting.

Holyrood elections always take place mid-term for Westminster governments, which means they are not fought on a level playing field. The governing party in power at Westminster is at a disadvantage, vulnerable to protest votes at Holyrood. The SNP has exploited this handsomely because it is forever in opposition in London. It won its first mandate in 2007 on the back of Tony Blair’s unpopularity. And in 2011 its landslide can largely be explained by the collapse in the Lib-Dem vote.

This is not to say that the nationalists owe their success entirely to outside factors. On the contrary, part of their success is attributable to their own astute positioning, and their skilled political tactics in ensuring that Lib-Dem voters defected to them instead of to Labour. Nonetheless it is patently absurd that Alex Salmond’s mandate to press for Scottish independence stems from voter unhappiness with Nick Clegg’s u-turn on English university tuition fees.

Both in theoretical constitutional terms, then, and in terms of raw political self-interest, it makes sense for unionists to change the devolved arrangements so that Holyrood elections happen at the same time as Westminster ones.

This begs the question, if the elections are simultaneous, is it sensible to have a different set of constituency members standing for each parliament, on different boundaries? This is a recipe for even greater voter confusion than already exists. Given that there is not supposed to be any overlap in the responsibilities of Holyrood and Westminster, it should be perfectly feasible to have the same MPs dividing their time between both parliaments. Their workload would be no greater than that of existing English MPs.

Such a change would open up opportunities for further reform. There is no real need for a country of Scotland’s size to have as many as 129 parliamentarians focussed purely on devolved matters. A body of 50 plus should suffice. The top-up ‘list’ MSPs could be scrapped altogether, or else converted to a revising body which would use the chamber on the days when MPs were on Westminster business.

These arguments have been put forward before of course, usually by small-government liberals aghast at the unwarranted proliferation of politicians that has come with devolution. The trouble is that the same people have often been sceptical of devolution itself, and so this point of view has generally been dismissed as the wishful thinking of ultra-unionist recusants.

But the political problems that devolution in its current form throws up have now become manifest, especially to the Labour Party, which must now be cursing the whole edifice. Devolution at the moment is an existential threat to Labour, and so everything must be back on the table. Simultaneous Holyrood and Westminster elections with combined MPs solves the West Lothian question on terms that Labour can accept, as well as eliminating the protest vote phenomenon that so favours the nationalists.

Such reform of Holyrood would be controversial. On its own it could be portrayed by nationalists as a betrayal of the principle devolution itself. But in the wake of an independence referendum, nationalism would be in disarray, at least temporarily. A UK government could impose a new settlement without fear of a new independence referendum for a decade at the very least.

But in practice there need be nothing for nationalist sentiment to feed on. The arguments in favour of combined elections are sound in themselves. And reform would come as part of a package which would necessarily include the devolution of more powers to Holyrood.

It would be very difficult for the SNP, defeated in a public vote, to make substantial political capital from reforms that enhanced the powers of the Scottish Parliament while reducing the number of politicians.

Politicians who win important elections find themselves in a position of strength where almost anything goes. No election will be more important than the vote on independence. The unionists must be prepared to use their victory – if it comes – to the full.