Scotland and England have been united for more than 300 years. Calls for independence have only grown louder in the last few decades. By 2012, the Scottish National Party’s ambition to put independence to the vote had become unstoppable, forcing the British to agree to hold a referendum.

Our envoy in Edinburgh, Joanna Gill, said: “The road to referendum has been a long one, but it went into overdrive following devolution in 1999 [see below]. It was thought this would kill nationalism stone dead. So why didn’t it?”

According to historian and journalist David Torrance, devolution might have killed those ambitions.

Torrance said: “Initially, it looked as if it had; the SNP didn’t do that well. But over time, of course, the mere existence of the Scottish parliament gave the SNP scope to expand their support, expand their representation and of course get into the government, and once they had their foot in the door it enabled them to grow even bigger, also to push for a referendum, and that is where we’re at.”

The SNP surpassed the mainstream political parties in Scotland, with a landslide victory in the Scottish Parliament elections in 2011. Labour, the Conservatives and the Liberal Democrats had all been discredited by scandals, a perceived mishandling of the financial crisis and unpopular austerity policies. The SNP capitalised on this.

Historian Tom Devine described the party’s gradual rise in popularity: “In the 1950s, it was regarded as a lunatic fringe. So what happened, first of all, was the switch from ethnic nationalism to civic nationalism. That is, it didn’t really matter where you were born as long as you supported the cause of independence. And then the other thing: it stole the clothes of old Labour. The modern Scottish National Party is actually more Labour than Labour.”

Many Scots saw New Labour as the executors of Margaret Thatcher’s Conservative policies. Her government’s sweeping de-industrialisation in the 1980s led to mass unemployment, especially demoralising for Scotland and other parts of northern Britain. Though some note she had some 30 per cent of the Scottish vote for most of her premiership, the Iron Lady became a figure of hate.

Tom Webster, at Edinburgh University, suggested Scots felt reduced to test subjects: “The biggest legacy of Thatcher is that feeling of being a space to try out new policies before they have to try them out on England. So it’s that strong sense of being a laboratory for English interests.”

Thatcher was a lightning rod for anti-Westminster, anti-Conservative ire, but North Sea oil also kept being cited as a pro-Scottish independence conduit, an increasingly convincing argument.

Torrance said: “Certainly, over the last couple of years, we’ve never stopped talking over North Sea oil – not as much of an issue (today) because it is now a diminishing resource. (But) In 1979 and for much of the 80s, it was pouring a colossal amount of money into the UK treasury and therefore, in the Scottish context, in the context of the independence debate, it played a much larger role.”

Whatever way Scotland votes, the referendum has already changed the United Kingdom’s political landscape. Experts say it is very far-fetched to think we’ve heard the last word on Scottish independence.

Devine said: “The genie is out of the bottle and it will not be put back in again.”

Our voice in Edinburgh, Joanna Gill summed up: “Unionists had been hoping for a wide majority in order to put calls for independence to bed, but recent polls have made that result unlikely. No matter what the outcome, the Scots have made their mark on UK history and all eyes now are on the country’s future.”

[The Scottish Parliament convened on 12 May 1999, following the Scotland Act of 1998.]