Readers in other parts of the UK may not be all that familiar with Patrick Harvie, co-convener of the Scottish Green Party (SGP). But north of the border, the Glasgow MSP has been a mainstay of the devolved political landscape for the best part of a decade, as well as one of its most consistently radical and provocative figures. So the significance of his latest intervention in the independence debate should not be underestimated.
Speaking to Holyrood magazine last week, Harvie hinted that he might be willing to abandon his traditional support for full Scottish self-government in favour of an enhanced devolutionary settlement: "(Independence) is not a point of principle for me", he said. "It's purely pragmatic...(and we) may want to refine the policy a bit - particularly if there's a third option (on the ballot paper)". This position was confirmed by an SGP spokesperson, who told the New Statesman that the Greens' constitutional stance was "not set in stone".
Despite the SGP's marginal status in Scottish politics - they have just two MSPs out of 129 - this could be an important development. The unionists' referendum strategy is to cast the SNP as a minority pressure group out of touch with mainstream, pro-devolution opinion. If effective, this will compound the suspicion that the nationalist surge is a temporary aberration at odds with Scots' fundamental desire to remain part of the United Kingdom. One way the SNP can avoid this is to form a united front with other, smaller independence-minded parties and organisations, of which the Greens are by far the most prominent. Failure to build such a coalition could just tip the balance of odds against a Yes vote in 2014.
But unionists shouldn't get excited quite yet. It's no secret that Harvie feels Alex Salmond is shutting non-SNP pro-independence voices out of the Yes campaign, so it's possible his comments were really a veiled bid for greater involvement. They may also be a reflection of the Greens growing antipathy towards the SNP as the party of devolved government. Over the last five years, the SGP has become more and more critical of the nationalists. Much of their hostility is a response to what they see as the SNP's tendency to side with the interests of big business over those of the environment, with the first minister's vocal support for Donald Trump's golf course development in Aberdeenshire and the construction of a second road bridge over the Firth of Forth being the main ca! ses in point.
Yet despite these policy disagreements and the general bad feeling between the two parties, it remains probable that the Greens will still campaign for outright independence over the next two and half years. One of the major prizes of full self-government would be the power to force the removal of the British nuclear deterrent from its current home on the Clyde - a longstanding ambition of the Scottish environmental lobby. This would not be possible under maximum devolution or federalism, both of which would see defence and foreign affairs remain under Westminster control.
The fact, though, that they are even threatening such a dramatic shift in position reveals just how strained the SNP's relations with other parties in Scotland are, including those with whom it should be on good terms. Given most polls show a majority of Scots continue to oppose the break-up of Britain, the nationalists simply can't afford to further alienate any of their would-be allies.