On 23 January 2013 the prime minster called for an "in/out" referendum on whether Britain should remain a member of the EU. During the questions following his speech he discussed the SNP's Scottish independence referendum and talked about the democratic rights of the Scottish people to decide their own future. However, in taking this stance Mr Cameron has now driven the British government into a cul-de-sac and he doesn't have a reverse gear. It would appear that Mr Cameron hasn't considered a couple of very important scenarios. For example:-
Scenario number 1:-
The SNP loses the Scottish independence referendum in 2014 and a form of Devo-Max is introduced across the UK. Scotland and Wales keep their national identities whilst England is broken up into nine regional pieces. Two years after this in 2017 the EU "in/out" referendum is undertaken and the results show overwhelming support for EU membership from the Scottish and Welsh populations but complete rejection from the English regions, who due to the size of their combined population dictates a withdrawal from the EU. The SNP would shout very loudly that the democratic rights of the Scottish were being ignored and trampled upon. The Scottish government along with the Welsh government would have a legitimate right to claim that the British government was forcing its will onto both the Scottish and Welsh people. Due to that claim the SNP could instigate a second independence referendum, whilst Plaid Cymru could instigate their first independence referendum for Wales. However, this time all the pro EU political parties would be supporting independence for both countries. The dissolution of the UK would occur and potentially the social union could become a hostile relationship between the nations of the UK due to their different relationships with the EU.
Scenario number 2:-
The SNP wins the Scottish independence referendum in 2014 and refuses to call for an in /out EU referendum. The EU countries annoyed by the British government's attempted tactical negotiations with them use the potentially fatal internal problems faced by the countries within Britain to clearly state that all former negotiations with the EU were by a British government that no longer legally exists. They seize the opportunity and state that Scotland, England and Wales now need to negotiate completely different terms with them. Scotland and Wales embrace the EU without calling for an "in/out" referendum but a British government that now only controls England which is heavily influenced by a new anti EU Englishness pushes ahead with an in /out referendum and England leaves the EU.
David Cameron's pronouncement of an EU "in/out" referendum has created a number of scenario's that the UK might face, some have far reaching consequences if we want to maintain a stable social union between our different national groups. You only need to look at our islands history to see our troubled past - stable working relationships can quickly change. Only arrogance and ignorance would tell you that history won't repeat itself.
Of course, David Cameron's dilemma can be avoided. If he supported a structured national federal system with a coherent foreign policy that fairly represented all the nations of the UK then he would be able to argue that he had a mandate for the UK. However, to do that he would need to create an English executive and he would need to do so very quickly.