Sorry. Romaz, but you are mistaken. Have a look at this list of sovereign states affiliated to the United Nations:
http://www.un.org/en/members/#s
You will find the United Kingdom of Great Britain and Northern Ireland. You will not find England, Northern Ireland, Scotland or Wales. The United Kingdom is a single sovereign state, a constitutional monarchy with one monarch, one government and one sovereign Parliament. The devolved assemblies (sometimes referred to as “Parliaments”) serving Northern Ireland, Scotland and Wales are responsible for specific (and limited) devolved powers ceded by the Westminster Parliament. These devolutions are similar in principle to the powers devolved to County Councils and Metropolitan Boroughs.
If you read this Wiki article:
http://uk.ask.com/wiki/United_Kingdom
You will note in particular: “The United Kingdom of Great Britain and Northern Ireland (commonly known as the United Kingdom, the UK or Britain) is a sovereign state...” and “The United Kingdom is a unitary state governed under a constitutional monarchy and a parliamentary system, with its seat of government in the capital city of London. It is a country in its own right...”
If you look at this Wiki article on Scotland:
http://uk.ask.com/wiki/Scotland
You will see “The Kingdom of Scotland emerged as an independent sovereign state in the Early Middle Ages and continued to exist until 1707...[the date of the Act of Union].
As far as the Scottish Parliament’s powers are concerned, these are governed by the Scotland Act, 1998 (a UK Act passed by the Westminster Parliament):
http://www.legislatio...kpga/1998/46/contents
You will see Section 37 determines that the 1707 Act of Union is applicable to the 1998 Act and if you read through the remaining 131 sections you will find no provision for the Scottish Parliament having any powers to alter the State of the Union.
I don’t know how much clearer I can demonstrate my contention.