Scotland has set a date for an independence referendum to decide if its five million people should end a 300-year-old union and leave the United Kingdom.

First minister Alex Salmond says the vote will be held on September 18, 2014.

Voters will be asked a single question: "Should Scotland be an independent country?"

Announcing the date in the Scottish parliament, Mr Salmond said a break of ties with London would give Scots the chance "to build a better country".

"The choice becomes clearer with each passing day - the opportunity to use our vast resources and talent to build a better country, or to continue with a Westminster system that simply isn't working for Scotland," he said.

Mr Salmond's pro-independence Scottish National Party (SNP) won a majority in the Scottish parliament in elections in May 2011.

But the SNP faces a hard battle to win the referendum, which will take place in the 700th anniversary year of the Battle of Bannockburn, a celebrated victory over the English.

Opinion polls put support for independence at about 30 per cent of the Scottish electorate, while 50 per cent favour the status quo.

The SNP complains that the British parliament, where members representing Scotland are a small minority because England has a much bigger population of 53 million, does not have the interests of the Scottish people at heart.

The Scottish parliament, established in 1999, has limited powers in areas like health and education but the British parliament at Westminster in London still exercises control over important government spending decisions and areas like defence.

The SNP argues that North Sea Oil revenues combined with the local farming, fishing and whisky industries would enable an independent Scotland to prosper.

Other parties in Edinburgh and the London government say both Scotland and the rest of the United Kingdom would lose out.

Critics of the SNP say its sums do not add up because oil reserves are dwindling and Scotland would lose the disproportionately generous share of taxpayer money raised across Britain that it currently receives.

Ramifications

A secession by Scotland would also pose serious challenges to the remainder of the United Kingdom, such as what to do about its Trident nuclear submarine fleet which is based in Scotland.

It could also have ramifications for the United Kingdom's status in such bodies as the G7 group of industrialised nations and as a permanent member of the United Nations Security Council.

The leader of Scottish Labour, the main opposition to the SNP in the Scottish parliament, accused Mr Salmond of setting a faraway date for the referendum to give himself time to turn the tide of public opinion, putting Scotland "on pause".

"The truth behind the delay is...Alex Salmond knows if he held the referendum now, he wouldn't just lose it, he would be routed," Johann Lamont told the parliament.

Mr Lamont accused Mr Salmond of dodging tricky questions such as what control the Bank of England would have over an independent Scotland if it retained the British pound as its currency, as he advocates, or whether an independent Scotland would remain part of the European Union.

Scotland already has many of the trappings of an independent nation such as its own flag, sports teams, and a history of achievements in science and literature.

Scotland and England have shared a monarch since 1603 and have been ruled by one single parliament in London since 1707.

Mr Salmond has said an independent Scotland would retain Queen Elizabeth as its monarch.

The broad terms of the referendum were agreed by Salmond and British prime minister David Cameron last October.

As part of the deal, Mr Salmond obtained the right for people aged 16 and 17 to take part in the referendum, a factor that could help the "yes" campaign as polls suggest younger people tend to be more favourable to independence.

Reuters