The United Kingdom will be changed for ever as a result of next week’s independence referendum - whichever way Scotland votes.
For a start, if the Scots vote to quit the UK it will give the Conservatives a boost and make it harder for Labour to win a general election.
Gateshead Labour MP Ian Mearns said: “I think we’ve got to be concerned because it could have an impact on what happens in the rest of the UK in terms of electoral prospects.
“If it makes the chance of getting a better Government elected, that’s got to be bad.”
A Labour victory would still be possible. Looking at the history books, there are just two occasions when a Labour government depended on Scottish MPs for a majority in the Commons - in 1964 and October 1974.
And without Scotland, Labour would still have won in 1997, 2001 and 2005.
But the result in 2010 would have been different without Scotland, and the Tories would have formed a majority government without requiring a Coalition with the Liberal Democrats.
Labour can potentially win next year’s election without Scotland, but Labour leader Ed Miliband’s task will certainly be harder if Scotland goes.
His party currently has 40 of Scotland’s 59 Westminster seats (far more than the SNP, which has six).
Opinion polls put Labour in the lead, but not by much. Clearly, losing 40 potential seats would damage Labour’s chances.
A “yes” vote would also raise difficult questions about what exactly should happen at the election.
Scotland won’t actually become independent until 2016 at the earliest - which means Scots would still vote in the next election, in May 2015, and elect MPs even if they only sat in Parliament for a year or so.
Scottish independence could also have an economic impact, possibly hurting the North East in particular.
North East Labour MEP Jude Kirton-Darling said: “There is also a risk to what remains of the UK, with academics suggesting that the imposition of a border could lead to a slump of 4% in trade, hitting both Scotland and the North East.
“This would hit the North East economy at a time when it is only just starting to recover and would set the region back.”
There are fears that an independent Scotland, depending partly on North Sea oil for revenue, will increase taxes on energy, pushing up costs for industry in England.
The Scottish government, in a paper setting out plans for independence, has promised to cut Corporation Tax by 3p.
This could force the United Kingdom to follow suit, to prevent businesses re-locating to Scotland, leading to a “race to the bottom” as both countries compete to offer the lowest tax rates to employers.
While there would be need for border controls as things stand, this could change if an independent Scotland adopted softer immigration controls than the UK.
But what if Scotland votes “no” to independence? The United Kingdom would still change dramatically - although nobody is sure quite how.
Scots already make their own decisions about issues such as health and education.
But the Scottish Parliament has been promised new powers over borrowing, income tax and welfare if Scotland remains in the UK. This is an option known as devolution max or “devo max”.
The trouble is that, as things stand, Scottish MPs at Westminster will continue to have a say about English education, health, welfare and so on.
But English MPs won’t even be allowed to talk about what happens in Scotland.
It’s not a new problem. It’s been an issue since the Scottish Parliament was established in 1999.
But if Scotland gets even more powers, there will be growing demands to do something about it.
This could mean banning Scottish MPs from voting on English issues in Parliament. It could even mean creating a special English Parliament.
Even if English politicians try to ignore the problem, they won’t be allowed to - because Carwyn Jones, the Labour First Minister of Wales, is demanding a “constitutional convention” thrash out how the UK should be governed.
Wales already has its own assembly, but he says it should have more power.
And if the Scots get everything they have been promised, any Government at Westminster will find it hard to tell the Welsh they can’t have the same. They will also be afraid that upsetting the Welsh too much could lead to another independence movement, this time based in Cardiff.
Something would have to change, says Brian Hall, who co-ordinated the independent campaign for a North-East Assembly in 2003.
He said: “It opens up a Pandora box in terms of Westminster. The English question becomes even more significant.
“An English Parliament could be an option. Equally, assemblies across a reshaped Britain could be another.
“The impact is going to big, particularly in the North East and other Northern regions.”