THE passage of the legislation allowing Theresa May to enact Brexit has started off a new war of words between Westminster and Holyrood, with calls for a new referendum on Scottish independence.

Certainly, the UK has its fair share of shortcomings. Despite repeated, often half-hearted, efforts at devolution, the UK remains one of the most centralised countries in the western world. Our research has found that real devolution, even just to match the G7 average, could bring increases in GDP per capita worth more than £2,000 for every person in Scotland. Whether through independence or devolution, more power must be taken from Westminster.

But if we are to have a re-run of the 2014 referendum, there are several questions that nationalists must be ready to answer. These are far from insoluble (and indeed, I would argue, solved quite easily), but whatever answer the independence movement wants to give, it must be in place and properly researched well in advance of polling day.

The first question, once again, will be the question of the currency Scotland would use. In 2014, George Osborne made hay claiming he could block Scotland from using sterling. The most polite thing we can say about this claim is that it is a legal fiction. Any country can decide to use whatever currency they want, and Scotland would be well within her rights to continue to use sterling.

But this question of currency quickly moves us to another – if Scotland were to re-join the European Union, would she have to adopt the euro? Well, yes and no. Obviously, Scotland will be required to ‘commit’ to joining the euro, as every member country (except Denmark and the UK) has done before. However, as we have seen in countries like Poland, Sweden and the Czech Republic, there is a big difference between ‘committing’ to join the euro and actually giving up the zloty, krona or koruna. Clearly, while joining the euro is a paper commitment that every country makes, there is no actual evidence that it will ever be enforced.

Of all the questions raised about independence, the question of whether Scotland is big enough to succeed in the world alone strikes me as the most ridiculous. When we look at the 193 listed states in the world, an independent Scotland would easily fit in towards the middle of the pack in population, and in the top third for GDP size. Indeed, looking at Scotland’s independent neighbours should make us ask what is going wrong in Scotland today – New Zealand, Denmark, Ireland and Finland have similarly sized populations to Scotland but have significantly larger economies!

But, you will hear from Unionists, what about the size of the Scottish deficit? Well, this one is potentially a major stumbling block for an independent Scotland, if she wanted to keep the exact same range of policies currently being pursued by Westminster and Holyrood. But Holyrood having the power to set policies around welfare, immigration and employment policy that suit the needs of Scotland, rather than the demands of Westminster, could easily lead to improvements in growth – assuming that opportunity is used to enact robust economic policies.

Fundamentally I, as an Englishman, have no say in this (and nor should I). The question of independence is a matter for the Scottish people, and you will decide. But whether Scotland stays in or leaves the UK, we need a fundamental rethink of how our country is constituted. And when the questions above are asked in the referendum, the Nationalists will have to have answers if you want to change the minds of those who stayed with the Union in 2014.

Mark Littlewood is Director General of the Institute of Economic Affairs