Westminster has been gripped by talk of a referendum this week. But the excitement hasn’t been about the vote in ten months’ time that will decide whether Scotland remains part of the United Kingdom, but about the possibility of an EU referendum in four years’ time. South of Hadrian’s Wall, Scotland’s vote on independence is fast in danger of becoming the forgotten referendum.

If the Scottish referendum is the forgotten one then the Welsh one is the one ‘nobody’s ever bloody well heard of’. Last week, David Cameron announced that there would be a vote in Wales to decide whether the assembly there should be able to vary the rate of income tax. This is, by any reasonable standard, a significant change to the fabric of the United Kingdom. Yet, in a sign of how inured we have become to constitutional tinkering, it was not front-page news in the London press.

This diet of constant constitutional change is putting the Union in danger. Too often these new arrangements are being pushed through for tactical, rather than strategic, reasons. When I pushed one senior Cameroon about the rationale for devolving income tax varying powers to Wales, he responded by pointing to the number of marginal seats there.

Nowhere are problems being stored up for the future more than in the Scottish referendum campaign. Better Together, which is running the effort to keep Scotland in the United Kingdom, have been at pains to stress that a No vote is not a vote for the status quo. Why? Because they know that more powers for Holyrood is a popular position. They responded to the news of more devolution for Wales by proclaiming that not only is the Scottish parliament receiving more powers because of last year’s Scotland Act but that ‘all of the parties are currently working on proposals to strengthen Holyrood even further. The only people standing outside this process are the SNP.’

Alistair Darling, who is leading the Better Together campaign, has made clear that, ‘If we vote to stay in the UK, I’ve always argued that devolution is not a concluded business. Undoubtedly there will be further measures.’ While David Cameron, in his only major intervention to date in the Scottish debate, promised last February that if the Scots vote to stay in the Union, he’d look again at the devolution settlement. As he himself said, ‘That means considering what further powers could be devolved.’

This approach might be the right way to minimise the pro-independence vote next year. But it risks a rejection of independence in 2014 being a pyrrhic victory for the Union. First, it offers the nationalists an opportunity that they can use to reopen the debate. They will argue that the Scots only voted ‘No’ because they believed that a slew of extra powers were coming to Holyrood. They will then claim that the devolution that has occurred is insufficient and that the Scots must be given a fresh choice.

Second, devolution has not, as George Robertson — one of its architects — claimed it would, ‘killed nationalism stone dead’. Instead, it has given a platform to the SNP that it would never have gained at Westminster. As long as there is a parliament where the SNP regularly holds power, the independence issue will never go away. It is, after all, the party’s reason for being.

The third and perhaps most important reason is that further devolution to Scotland will exacerbate the West Lothian problem. At the moment, Scottish MPs can still vote at Westminster on devolved matters. So far, English voters have proved remarkably unbothered by this asymmetry. But the outcry over the decision to keep shipyards on the Clyde open at Portsmouth’s expense suggests that English attitudes are hardening.

In cabinet there are those who believe the West Lothian question has to be answered before there is further devolution. One senior cabinet minister tells me that he would fiercely oppose any new Scottish settlement which did not contain such an answer.

At the last election, the Tories were committed to English votes for English laws. But the more powers that are devolved to Scotland, the more difficult this change becomes to enact. Under this system, one could easily have a United Kingdom government that did not have a Commons majority on a host of issues. What would happen if, say, a Labour government had stood on a manifesto of rolling back public service reform but then didn’t have an English and Welsh majority in parliament for those changes?

To the Liberal Democrats the answer to this question is clear: home rule for all. But it is hard to see how federalism could work in the United Kingdom given England’s size; England makes up more than 80 percent of the UK population.

An English parliament would be a body of outsize importance. It is all too easy to imagine how this situation would lead to a clash of legislative egos. Who would be the power in the land, the English first minister or the Prime Minister of the United Kingdom? The stock response to this question is to suggest a series of regional English assemblies. But, as the overwhelming rejection of regional government for the North-east in 2004 showed, there is little appetite for that.

The Union is also being endangered by the fact that we are becoming less and less aware of what is going on in the rest of the United Kingdom. This problem is compounded by the message from Edinburgh that it is best for the English to stay out of Scottish debates.

Alex Salmond will publish his white paper on independence in just over two weeks’ time. It will set out the mechanics of how Scotland would leave the United Kingdom if it voted for independence. Tellingly the UK government’s planned attack on it, of which The Spectator has seen a copy, concentrates on the practical problems of independence, not an impassioned defence of the Union. There’ll be a blast from Danny Alexander on an IFS report on the fiscal implications of independence and Whitehall also wants to reignite the debate about whether an independent Scotland could negotiate EU membership within 18 months.

Uninspiring as this response may be, the polls suggest it will be enough. The real danger, though, is that the ties which bind Britain together are being so weakened that victory in the referendum will offer only a temporary respite for the Union.