MARK Smith writes that “I don’t think anyone would suggest a repeat of the 40-per-cent rule” ("A Holyrood majority should not mean referendum re-run", The Herald, September 16). Really, Mr Smith? For right on cue, in your Letters pages, David Roxburgh writes arguing for independence to be supported by 60 per cent of those voting in any future referendum.

Presumably, if polls suggest support stands at or near that figure the barrier could be raised to 66 per cent, or 60 per cent of those registered to vote?

READ MORE: Petition launched to require two-thirds majority for independence 

Mr Smith does not seem to understand that in UK democracy the tradition has been that success is one vote more than anyone else. For instance, much to the great surprise of public opinion, David Cameron won a majority at the 2015 election. This allowed him to hold the in/out EU referendum the following year, and as a result of this the UK will shortly leave the EU. However, not only was the EU vote determined by four per cent of the votes cast, but Mr Cameron won his majority in the 2015 election with 36.9 per cent of the vote. Yet when the SNP won a majority of seats in Scotland in 2017 with 36.9 per cent of the vote (in Scotland) we were told this represented a setback to the independence cause.

For instance, the Liberal Democrats have chided the country for a year about a “People’s Vote” but now consider this unnecessary – a general election success would be enough. However, Mr Smith refers positively to a suggestion that independence should as a matter of course be confirmed in two successive referenda. “Success” has become malleable, what the speaker’s interests need it to be.

But, for the Unionist side, all obstacles increasingly lead to independence. I don’t think anyone would argue against the proposition that a referendum’s outcome is better supported by a large majority than a marginal one, but surely all referenda need to be run along the same rules and requirements and, if they are to be changed, should it not be for reasons other than political expedience? Is that too much to ask, or is consistency contingent on the matter in hand?

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This point seems to have escaped Mr Smith when he writes that Scottish nationalists and Brexiters would resist changes to the established rules, because, “they want it to be as easy as possible to win”. Yet is not equally true to say that those suggesting such changes, even while they wrap themselves in fine-sounding phrases such as “established will” also “want it to be as easy as possible to win”?

Willie Rennie’s interventions over the weekend, Mr Smith’s article and Mr Roxburgh’s letter are all attempts to redraw what a “mandate” for independence should look like and as support for independence increases, we can reasonably expect the obstacles to do likewise. The focus is shifting from winning the argument to redefining what winning means.

Alasdair Galloway, Dumbarton.

DAVID Roxburgh’s letter (September 16) is a masterpiece, unambiguous and as clear as a mountain stream and filled with good sense.

The only point with which I would disagree, slightly, is his suggestion that a 60-40 rule be applied to all referendums. As it is in the United States, a two-thirds majority would be much fairer for all constitutional referendums in every corner of the UK.

Alexander McKay, Edinburgh EH6.

WILLIE Rennie bases implacable opposition to a second independence referendum on a "promise" that the 2014 vote was a "once in a generation" event. As Nick Clegg could remind him, campaign promises can come back to bite political parties. Sir Nick "promised" not to increase university tuition fees. He did. Better Together "promised" that voting No would secure Scotland’s place in Europe. It didn’t. The SNP’s promise in its 2016 Holyrood manifesto was conditional: the Scottish Government should have the right to hold a democratic event "if there is a significant and material change in the circumstances… such as Scotland being taken out of the EU against our will". Dragging Scotland out of the EU defies the 62 percent who voted to remain. No democrat should deny Holyrood the means of honouring such a clear vote.

READ MORE: A pro-independence majority at Holyrood is not a mandate for another referendum

Simply setting aside the EU referendum result might be the LibDems' latest style but Mr Rennie would do better to observe the Edinburgh Agreement’s aspirations for the referendum. Its terms sought a process that "should deliver a fair test and a decisive expression of the views of people in Scotland and a result that everyone will respect". The 2014 loss of the referendum was followed by an unprecedented SNP landslide in 2015; SNP majority of seats in 2016 and 2017; an overwhelming SNP majority in 2019’s EU election. These indicators, plus opinion poll increases in support for both independence and a second ballot, suggest that the people of Scotland – to whom politicians are accountable – appear increasingly minded not to respect the result from 2014. If the single expectation was that the result would command respect there was no indication that that respect would be mandatory. The "settled will" of 74.26 percent in Scotland who voted to reconvene the Scottish Parliament has been respected; the No vote settled nothing.

Before Mr Rennie boxes himself into a "no deal" position he should reflect on Scottish historical intellectual flexibility. Hugh MacDiarmid observed that the "constant effort" of Patrick Geddes was "to help people to think for themselves, and to think round the whole circle, not in scraps and bits". Scotland’s independent future maps onto that "whole circle" of which collaborative, broad and cross-community consensus will form part. As MacDiarmid observed of Geddes "he knew that watertight compartments are useful only to a sinking ship". Mr Rennie might want to rethink the benefits of participating in a multi-party consensus rather than allowing the LibDems once again to be shipwrecked by the bad politics of Westminster.

Dr Geraldine Prince, North Berwick.