There has been almost as much speculation about the timing of the Scottish National Party’s (SNP) referendum on independence as there has been about the outcome of the referendum itself. One common interpretation is that the autumn 2014 date was chosen because it roughly coincides with the 700th anniversary of the Battle of Bannockburn. Ask any SNP politician and they’ll tell you this is nonsense. The real explanation is that SNP strategists believe Scottish voters will become increasingly susceptible to the appeal of complete political separation from England the closer they get to a Westminster election the Conservatives look likely to win.
The problem for Alex Salmond and his allies in the Yes Scotland campaign is that the odds on David Cameron achieving a second term seem to be steadily diminishing. When the SNP leader revealed his referendum timetable back in January, the Tories enjoyed a lead of five per cent  over Labour. The slump in Labour support was precipitated by a string of weak performances by Ed Miliband at Prime Minister’s Questions and a damaging spat with the unions over cuts. Today, following George Osborne’s disastrous budget and the British economy’s slide back into recession, the situation is transformed, with Labour leading the Conservatives by as much as 13 points . What’s more, the confidence of the British public in the Conservatives to manage the economy effectively - an important indicator of any government’s success - has been shattered .
All this bodes well for Labour, but it should be equally encouraging for supporters of the Union: a sustained revival in the party's electoral prospects could seriously damage nationalist hopes of securing independence in two years time. Scottish political culture is to a large extent defined by its anti-Conservatism. Scots see Labour as the most reliable safeguard against the Tories at Westminster and, these days, the SNP as the most effective advocates of Scottish interests from an Edinburgh base. This translates into the constitutional sphere as well. The decisive factor in the reversal of Scottish attitudes towards devolution between 1979 (when just over 50 per cent of voters backed a Scottish legislative assembly) and 1997 (when nearly 75 per cent did) was 18 years of Tory government. This means that if the prospect of an extended period of Tory rule continues to deteriorate over the next 18 months or so, the nationalist argument that independence is a necessary bulwark against the English right could begin to lose its force.
Yet, in terms of the bare politics of the referendum campaign, Labour continues to make bad tactical and strategic errors. Two weeks ago, Miliband - displaying a remarkable disregard for Scottish political sensibilities - said he was “sure”  Tony Blair would play a significant role in the fight to save the Union. But nothing would delight nationalists more: by 2007 Blair’s unpopularity in Scotland was so great it helped propel the SNP to power at Holyrood for the first time. The continued support of both the UK and Scottish Labour leaderships for Britain’s Clyde-based nuclear deterrent hands the SNP another campaigning advantage. Most Scots oppose  the renewal of Trident, and Alex Salmond will be sure to place his pledge to remove it from Scottish waters at the centre of his case for secession. Finally, and above all, Labour’s refusal to articulate a radical devolutionary alternative to independence leaves the nationalists free to dictate the terms and conditions of the constitutional debate. Scots will be more likely to vote to leave the UK if the unionist parties fail to explain how they want the next phase of devolution to develop.
The challenge for Miliband is to incorporate his party's defence of the Union into a wider narrative of Labour renewal. Recent successes notwithstanding, the party still seems uncertain about how it should reconstruct its identity in the post-Blair era. A commitment to fully modernise the British constitutional system, including fiscal autonomy for Scotland and significant new powers for the Welsh assembly, might be a good way to start. Nevertheless, some members of Scottish Labour may be left wondering why they should look to Miliband and the UK leadership, rather than to Johann Lamont and her team, to secure Scotland’s future as part of the UK. The reality is that for as long Scottish Labour remains a subordinate and attenuated version of British Labour, it will always be a secondary player in the battle against the SNP.