THE European Convention on Human Rights (ECHR) had three main authors, a Frenchman, a Belgian and a Scot. David Maxwell Fyfe was the last of that trio, the Edinburgh-born Conservative MP and, later, judge and Lord Chancellor.

And, as the legal scholar Neil Duxbury explores in his new biography of Lord Kilmuir (as he became), Maxwell Fyfe was a bit of a visionary, arguing (in 1948) that "the danger to human rights is almost never of a sudden onset".

Rather it "comes gradually", with people often failing to notice as rights disappeared. It was therefore essential, added Maxwell Fyfe, for the 1948 "Congress of Europe" to "place on record its determination that it will help in securing that these rights are promptly, full and explicitly expressed".

Of course he said as much in the destructive wake of the Second World War; Maxwell Fyfe had been a prosecutor at Nuremberg and understood all too well how governments could gradually erode human rights. He had no truck, meanwhile, with those who resented the loss of sovereignty implicit in ratification of an international treaty. At the end of the day, he concluded, the UK could also un-ratify it.

Which, of course, is what the present Conservative Party once promised to do, although that now appears to have been watered down to the abolition of the Human Rights Act (HRA), the 1998 Act that makes it easier to enforce rights guaranteed by the ECHR in British courts without recourse to the European Court of Human Rights in Strasbourg.

And as the constitutional lawyer Aileen McCarg set out in these pages last week, what's actually proposed seems a bit of a muddle, for even if the UK Government manages to replace the HRA with a new British Bill of Rights, the Strasbourg route would remain. Ironically, therefore, it could end up making very little difference to the status quo.

But there is a strong symbolic element in all of this, for the same Tory MPs who get upset about Brussels also view the ECHR as an extension of the European super-state. So tackle the latter, runs the quixotic hope, and the former might become a little easier to manage. It falls, meanwhile, to another Scots-born Lord Chancellor, the mercurial Michael Gove, to square the circle.

Dominic Grieve (a former Tory Scottish affairs spokesman) has emerged as the chief Tory rebel, and as Attorney General between 2010-14 he has considerable credibility in his opposition to any dilution of the HRA or ECHR. Among his objections is the obvious problem of Scotland, Wales and Northern Ireland, whose respective parliaments and assemblies enshrine the ECHR, making it very difficult to unpick in three constituent parts of the UK.

As Mr Grieve observed in a cogent piece for The Times, at a time when the future of the UK was still in question, not to mention the fragility of the Northern Ireland peace process, his party's plans risked "serious political discord" which, for a party committed to the Union, would end up being "entirely contrary" to "fundamental" Conservative aims. It's in that context that Mr Grieve has found an unlikely ally in Alex Salmond; indeed the pair were spotted having lunch together at Westminster a few days ago. It seems clear-cut - both oppose David Cameron's plan to scrap the HRA - but as with the SNP's apparently simple stance on the UK's membership of the European Union (pro), underneath there lurk contradictions.

Since the new Parliament convened "the 56" have been quick to occupy the moral high ground on this point, not least because it differentiates progressive Scotland from regressive England. In a fine maiden speech, the QC-turned-MP Joanna Cherry, also the SNP's spokeswoman on justice and home affairs, reminded the House that she and her party were "fundamentally opposed" to repeal.

Ms Cherry, however, omitted to mention her party's opposition to prisoner voting rights, a stance at odds with an ECHR ruling that a blanket ban is a breach of human rights. In 2013 Nicola Sturgeon (who tomorrow speaks in Brussels for the first time as First Minister) resisted considerable pressure to enable at least some convicted prisoners to vote in the independence referendum, instead adopting a much harder line than most other political parties. Now Ms Sturgeon didn't say, like Mr Cameron, that the idea of prisoners being able to vote made her "physically sick", but her position was the same.

Writing in The National last week, the former Justice Secretary Kenny MacAskill said it was the "wrong thing done … for the right reasons"; that is, avoiding "needless distractions in the run-up to the referendum". In her maiden speech Ms Cherry twice railed against the influence of the "right-wing press", yet according to Mr MacAskill last year the SNP made the same calculation, setting itself against prisoners voting in order "to deny the right-wing press lurid headlines that could tarnish the bigger picture".

The Scottish Government, unsurprisingly, didn't bother responding to Mr MacAskill's allegation, in which he admitted being "complicit", for that, one suspects, would have lent it credence. But whatever the former Justice Secretary's motivation for writing the article (like Mr Grieve, he recently became an ex-minister), his central point was sound: unless the Scottish Government reversed its stance on prisoner voting rights then it risked appearing hypocritical in its critique of David Cameron's plan for a Bill of Rights.

Also conveniently forgotten is Mr Salmond's record. At Holyrood in 2010 he said that for "most people", prisoners voting was not what they "would consider to be an important human right" (he also appeared to believe the ECHR had been ratified by the UK in 1997 rather than 1953). In the latter half of 2011, meanwhile, quite a lot of the-then First Minister's time was spent attacking the UK Supreme Court on another ECHR-related matter.

That doesn't mean the SNP's exceptionalism on prisoner voting is necessarily without merit. Even Mr Grieve believes the ECHR's ruling in that regard demonstrated "an excessive trend to micromanage" and "a failure to allow for divergence of interpretation". Nevertheless, there is such a thing as trying to have your cake and eat it which, as Mr MacAskill recently revealed, best sums up the Scottish Government's approach.

In last week's Queen's Speech there was evidence of backtracking from the UK Government. So the SNP aren't alone in appearing confused on this matter; indeed, even David Maxwell Fyfe later abandoned the liberalism implicit in his support for the ECHR, becoming a decidedly right-wing Home Secretary, particularly when it came to homosexual law reform. But then as the blogger Lucy Hunter Blackburn recently observed, the moral high ground is a "complicated place … and not always the easiest one from which to exert leverage".