Expect more taxing questions ahead...

MSP John Mason's now infamous motion on same-sex marriages was uncompromisingly slated by his SNP MP colleague Pete Wishart. Mr Wishart courted further Nationalist strife by claiming the concept of 'Britishness' could be enhanced by Scottish independence. He then attracted further adverse headlines by suggesting that the SNP's "total and exclusive focus must be now on winning the referendum".

Which of course helped fill the silly season news vacuum during the gaps between the phone hacking scandal, the English riots and Libya.

But now it's Mr Mason's turn again, with his suggestion that Scotland should implement a top rate of income tax in excess of 50% evidently proving as popular with the SNP hierarchy as, say, a suggestion that independence could enhance Britishness.

But which is certainly at odds with the SNP's drive to implement a lower corporation tax rate in Scotland to attract investment in a competitive global market, since a business-friendly fiscal environment would be undermined by high rates of personal taxation. But the slightly bizarre thing here is Mr Mason's advocacy of a more competitive corporation tax regime in a planted question to Alex Salmond during a session of FMQs just before the Holyrood summer holidays. Then Mr Mason adduced the support of Clyde Blowers Capital for the proposal, but as pontificated here at the time this should have drawn attention to chief executive Jim McColl's status as a tax exile, which is presumably because of, er, unattractive rates of personal taxation.

Which serves to confirm the slightly contradictory nature of John Mason's latest proposal on income tax, and the plot is perhaps further thickened by his status as a chartered accountant.

However, perhaps the newsworthy status of these relatively minor SNP spats serves to underline the generally cohesive nature of the party in recent history, held together by the lack of a majority during their first parliamentary term of office and, moreover, any possible conflict dampened by the tantalising thought of the ultimate goal of independence.

Of course, with the current unpopularity of Scottish independence among voters necessitating a repositioning of the party to construct a form of greater autonomy that the public would buy in a referendum, this brings questions of substantive policy more to the fore, and hence the likelihood of real Nationalist splits on the various issues.

Hence at the weekend the SNP attempted to put the currency issue to bed, with a Scotland on Sunday article flagging up a commitment to retain sterling post-'independence'.

Of course, with globalisation, supra-national organisations and to that extent an increasingly interdependent world, the SNP has for some time had quite a bit of trouble on the issue of where sovereignty should lie. And with the EU likely to either split in terms of the eurozone or move further towards a European superstate to save the single currency, this will do nothing to help the SNP answer questions regarding what a post-'independence' Scotland would look like. The vexed issue of an independent Scotland's EU membership - how or whether it would gain admission and whether or not this would necessitate euro membership - is likely to become even more difficult in view of the uncertainly over Europe's future in the next handful of years, unfortunately for the SNP coinciding with the run up to the independence referendum.

Domestically this will be exacerbated by the SNP's threadbare legislative programme for the next few years. To a degree Pete Wishart was only stating the obvious when he said the party will need to exclusively focus on independence, if only because there will be little else to preoccupy the party, or indeed Holyrood, the press and the Scottish body politic generally.

But clearly the whole question of what independence would mean will come increasingly to the fore, and while the lack of Scottish riots this summer and the Westminster cuts agenda provide easy pickings for the SNP, the more difficult questions like the EU conundrum provide a significantly greater challenge.

One correspondent to the Courier recently claimed: "A vote in the forthcoming referendum is not a vote on the EU. It is not a vote on dog fouling, the Queen, or hanging or the eurozone or any other matter that gets folk wroched up. It is a national chance to vote for normality and become a nation again."

But, unfortunately for the letter writer, most folk will get wroched up about the substantive policy implications of independence, rather than merely seeing "normality" and "becoming a nation again" as ends in themselves.