EU referendum muddies the constitutional waters

Labour's Ed Miliband has been enjoying David Cameron's latest troubles over Europe immensely. It is redolent of the mess the Conservatives found themselves in during the early 1990s, when John Major was unable to control his own Eurosceptic rebels. But Mr Miliband may not be smiling for long, because things have moved on and Britain, or rather England, appears to be increasingly hostile to the European Union. The pressure will mount on Labour before the next General Election to give its own commitment to a referendum on Europe, especially if, as expected, Ukip effectively wins the European elections in May, 2014.

I don't see how the Labour leader can refuse. Indeed, both Labour and the Liberal Democrats already accept that there should be a referendum if there is any "substantial" change in Britain's relationship to Europe. Since Europe is in the process of reviewing the EU treaties prior to introducing a banking and fiscal union, that substantial change looks increasingly likely. Yesterday, at Prime Minister's Question Time, the Deputy Prime Minister and Liberal Democrat leader, Nick Clegg, said it was a matter of "when not if" there will be a referendum on Europe.

Europe has become the dominant issue in UK politics, and it increasingly looks as if Britain is, if not on its way out, then moving towards a much looser relationship. But where does this leave Scotland? We have a referendum on independence in September, 2014 in which Scots will be asked whether they want to be out of the UK but in Europe. Then, shortly after, they will be asked in a referendum whether we want to stay in the UK but out of Europe.

I don't know about the voters, but I'm confused. I'm not even sure it is possible to have a view on staying in the UK if we don't know whether Britain is staying in Europe.

Indeed, as the constitutional lawyer Alan Trench has suggested, there is a case for delaying the Scottish referendum until the UK's position in Europe has been resolved. This is because the information essential for making a determination on independence for Scotland will not be available to Scots when they make their choice in September 2014. Will a No vote also be a vote, effectively, to leave Europe – a proposition that a majority of Scots reject? We don't know.

Alex Salmond, ever the optimist, seems to believe that the very threat of a Tory Euro referendum will automatically deliver a Yes to independence in 2014. "The alternative is Scotland being dragged to the EU exit door against our will," says the First Minister. "A Yes vote means Scotland will remain in the EU as an independent member and a seat at the top table".

But I'm not sure that this necessarily follows. The Nationalists no longer believe in a stand-alone Scotland with its own currency and independent trading status. They want Scotland to retain the pound, the Bank of England, the social union and so on. If Scotland is in a currency and customs union with the UK, I am not sure how Scotland could remain in Europe if the UK pulls out.

To justify a Yes vote to stay in Europe, the SNP would have to be prepared to abandon the pound, join the European single market, and become an independent state outside the UK currency zone.

Some prominent figures in the Yes Campaign chair, Dennis Canavan, and the independent nationalist MSP Margo MacDonald, want the SNP to give precisely this commitment to an independent currency. But their appeals have been rejected by Alex Salmond and Nicola Sturgeon.

I understand the SNP's dilemma here. Its policy of keeping the pound and the social union made a great deal of sense. Scots were never going to vote for customs posts at Gretna Green and going to all the trouble of setting up a separate Scottish currency.

Scotland is not an oppressed nation, and is not seeking national liberation from England. Scots will only vote for independence if they can be pretty sure that things will remain largely as they are today, albeit with better economic powers for Holyrood.

However, by linking Scotland so closely to the "continuing UK" the SNP may have a hard job of persuading Scots in the referendum to vote for something that they aren't even proposing themselves: the idea of Scotland out of the UK single market but in the EU single market. Scottish voters may well decide that, given the uncertainty surrounding the UK's future, it is better to stick to the status quo for the time being.

There may even be a case for mass abstention in the September 2014 election. Most Scots will feel disenfranchised anyway because they are being offered two unacceptable alternatives: independence, which only a minority support, and the status quo, which even fewer want. The chairman of Better Together, Alastair Darling, has this week all but crushed any hope of there being a "better devolution" if Scots vote No. The former Labour Chancellor says that there would be no mandate for further powers for the Scottish Parliament unless it is put to the UK in an election manifesto. And if independence is rejected in 2014, we can be pretty confident that this will not happen.

2014 is looking like the wrong choice at the wrong time. The European elections of May 2014 – only four months before the Scottish independence referendum – will likely see Ukip sweeping the board in England. Scotland's referendum campaign risks being overshadowed by a clamour of calls for EU withdrawal.

This is not the right atmosphere in which to make a sensible decision about Scottish independence. The mood of the Scottish electorate is likely to be one of confusion and discontent. At the very least, there is going to be a large number of Scots standing in the voting booths, pencils poised, saying: what is this all about?