Canon Kenyon Wright does well to remind us of the fundamental difference between Scotland and England on the question of ultimate sovereignty, which is now critical in deciding the current constitutional argument about control of the forthcoming independence referendum (Letters, January 13) .

The concept of "sovereignty of the Crown in Parliament" was simply a device invented by Oliver Cromwell to clip the wings of the Stuart monarchs and keep them under the control of (the then English) Parliament. This concept is therefore a fundamentally English principle and has no counterpart in Scotland, where sovereignty has always rested with the people. This was clearly stated by Lord President Cooper in the 1953 Court of Session case of McCormick v the Lord Advocate. This Scottish constitutional position was re-confirmed as recently as 1989 in the Claim of Rights, signed by the leaders of all the political parties as well as by many representatives of churches, business and civic society in Scotland.

Despite this, it is now being suggested by Unionist leaders and supporters, (and some contributors to your Letters Pages) that the assumed sovereignty of the UK Parliament gives it ultimate and overriding authority over all constitutional matters throughout the UK, and that this was provided in the 1707 Treaty of Union. Having read through all 25 clauses carefully, I can find no trace of such a provision, and in fact the word sovereignty never appears in the document.

Article I simply confirms that "the two Kingdoms of Scotland and England will for ever after be united into one United Kingdom". Article III provides that "the United Kingdom shall henceforth be represented by one and the same parliament". The remaining 23 Articles largely relate to detailed provisions for the protection of commercial, trading and taxation rights for the residents of each country. There is no mention anywhere that the new united parliament will inherit the "Crown in Parliament "sovereignty principle.

It seems likely therefore that the UK Parliament, which since the very beginning has always had a large majority of MPs representing English constituencies, simply assumed the English sovereignty principle, and in 300 years this has never been legally challenged or even thought about. The 1998 Scotland Act routinely reserved constitutional matters to the UK Parliament, and it appears that the sovereign rights of the people of Scotland were ignored and never considered.

This question must now be properly resolved, and it seems that the only way is to refer it to the UK Supreme Court responsible for all constitutional matters.

Iain A D Mann,

7 Kelvin Court, Glasgow.

THE period between now and autumn 2014 gives all parties the chance to consider various options and agree on a question, or questions, best formulated to get a response from the people of Scotland that reflects the wish of the majority.

For this reason, a simple Yes/No question on Scotland leaving the UK is not appropriate and David Cameron is wrong to try to force it before the constitutional factors are addressed.Perhaps we should consider a federal system with proper tax-raising parliaments for Wales and Northern Ireland as well as Scotland, with Westminster becoming an English Parliament. The present House of Lords could become the Federal Chamber, thus solving the problem of what to do with it.

As to whether the Scottish Parliament has a legal right to call a referendum, Westminster politicians would do well to remember that sovereignty in Scotland lies with the people, as it has done since the Declaration of Arbroath, 1328, reaffirmed by the 1698 Claim of Right and preserved by the 1707 Act of Union.

If Westminster tried to declare a Scottish referendum illegal, the UN might have something to say as the Universal Declaration of Human Rights, article 15, states that everyone has the right to a nationality and that no-one should be arbitrarily deprived of a nationality or denied the right to change nationality.

Finally, though not a Unionist, I feel we desperately need a credible spokesman or woman for the Union. He or she must be Scottish and must not be Tory. The LibDems could return to their convictions and make a case for devo-max as a way of preserving the UK in an updated form and could surely suggest someone.

How about Charles Kennedy? For Labour, Douglas Alexander has made the right noises recently and Alistair Darling comes across as measured and statesmanlike.

Ann Rayner,

22 Saughton Crescent,

Edinburgh.