There are many potentially alarming lines in the world of politics – ‘we need to have a serious conversation about immigration’, ‘owning a gun is just a logical extension of free speech’ and anything equating unlimited political donations with having ‘a voice’.

The Manchester United manager Alex Ferguson has veered into this worrying terrain with his objections to the rule that those living outside of Scotland can only donate up to £500 towards either side of the independence campaign.

I can sympathise with a Scot living away from home and wanting to take part in the referendum but a rich individual complaining of being “silenced” due to donation limits rings alarm bells.

Donating £501 to a referendum campaign (as Alex has impudently done to make a point) is a far cry from the Super PACS in the USA where individuals can swing elections if they spend enough money, but both situations are wrong thanks to the same principle which is simply that in an ideal democracy, every citizen should have an equal say.

There is no doubting that there is a link between money spent and electoral success, if money moves polls then it can certainly move election results but is it fair that Alex Salmond can deposit £1m cheques from Scottish lottery winners and deceased Scottish poets but Better Together can’t cash a £501 cheque from English-based Scots? That’s debatable, but it is at least just as fair as the current law prohibiting donations from overseas benefactors, even from Scots such as Sean Connery.

Some may claim that the SNP is just trying to level the playing field with this rule in advance of the referendum campaign really getting going. My view is that there is nothing necessarily wrong with that.

I’ve often thought it dubious fair play that UK parties could bus in swathes of activists from across the country for single by-elections, at least in theory, so to make a Scottish referendum as distinctly Scottish as possible does have its merits. If that means that anomalies arise whereby Scots living outside of Scotland lose some influence in proceedings, be it through not having a vote or limited donations, then that to me is a price worth paying to ensure that it is the right people making the right decisions.

Some will disagree, and this is one of those prickly referendum issues where an objective solution cannot easily be disentangled from a partisan viewpoint. I want a Yes result in 2014 and, surprise surprise, I agree with the SNP’s argument here that too much money from outside of Scotland would tarnish the referendum process. Those seeking a No vote would no doubt disagree.

It is unfortunate but seemingly unavoidable that interested Scots seemingly take a party view on these issues, issues that shouldn’t intrinsically fall along pro- or anti- independence lines, and yet here we are. Much like devolving broadcasting or fiscal autonomy, it seems impossible to have a discussion on the merits of any single issue without it really being about constitutional positioning.

Alex Ferguson is entitled to a view and a voice on Scotland’s constitutional future, of course he is, but he shouldn’t expect to buy more of an influence than he is entitled to as just one of the world’s 6million Scots who just happens to have money to burn and, well, given he has top billing in the Scotland on Sunday today, I would suggest that he is getting his voice heard just fine.