At last, they’re off. Last week’s "Edinburgh Agreement" ended nine months of argument between the Scottish and UK governments over how and when the independence referendum should take place, and signalled the start of a two-year campaign to determine Scotland’s constitutional future.

But where do the nationalist and unionist campaigns stand and what challenges lie ahead? Last week’s Ipsos MORI poll provides many of the answers.

The poll headline reveals that support for Scotland becoming independent continues to decline. In January 2012, almost four in ten of those of those who told us they would definitely vote in the ballot agreed that Scotland should be an independent country. Today, that figure stands at 30 per cent, meaning that one in four supporters have deserted the nationalist cause in 2012.

At least some of this change in public mood was predicted during a year in which a sense of ‘Britishness’ was celebrated with the Jubilee and the Olympics. And this week's so-called ‘Scomni-shambles’, with two Scottish National Party MSPs resigning over the party’s new policy on NATO membership and the First Minister’s integrity being questioned over the legal advice sought about an independent Scotland’s future in the EU, won’t have helped the nationalist cause.

It is clear that it is the nationalists who face the stiffer challenge in winning the hearts and minds of Scottish voters. Firstly, there is the fact that only a quarter of women female voters (24 per cent) support independence, a full 13-points lower than support among men. The appointment of deputy First Minister Nicola Sturgeon to run the ‘Yes’ campaign is clearly aimed at encouraging more women to change their minds, but the scale of the deficit makes this a huge task.

Then there is the economic argument. It is clear that voters have yet to be convinced that they will be better off if Scotland were to go it alone. Our January poll showed that this will be the most important issue in deciding the outcome of the referendum and that voters felt less secure about their finances when they considered what life would be like in an independent Scotland. The current poll illustrates that it’s owner-occupiers (28 per cent), those with children (27 per cent) and those who live in the most affluent areas of Scotland (23 per cent) who are the most lukewarm about the prospect of independence.

These challenges are magnified by what is happening to support for the SNP and to voter satisfaction with the performance of the First Minister. In terms of voting intention for the Holyrood parliament, Labour has now closed the gap with the SNP from 25 points in December 2011 to just five points now. And while Alex Salmond continues to have personal ratings which all other leaders can only dream of (50 per cent are satisfied), these are also heading in the wrong direction, having been at 62 per cent just under a year ago.

The ‘No’ campaign has had an easier ride of late yet still faces its own challenges in persuading voters that Scotland is ‘better together.’ Their current healthy lead could be vulnerable if they are unable to outline and persuade voters of the additional powers to be devolved to the Scottish Parliament in the event of a ‘no’ vote. The majority of Scots want decisions about taxation, welfare and benefits to be made at Holyrood. However, with the option of further devolution not appearing on the ballot paper, it is up to the ‘No’ camp to outline a united, coherent vision or risk alienating voters who want further devolution but who currently want to remain in the UK.

Overall, those working for an independent Scotland face the bigger challenge in winning public support. Their hope is that 2012’s feeling of ‘Britishness’ will be replaced by ‘Scottishness’ in 2014 with the Glasgow Commonwealth Games and the Bannockburn commemoration. The danger is that, by then, it may be too late.