By Andrew Osborn
LONDON (Reuters) - Scotland will become independent of the United Kingdom on March 24, 2016 if a majority of Scots vote to end their 306-year-old union next year, the Scottish government said on Sunday, naming its "date with destiny" for the first time.
Scotland's devolved government, which is controlled by the Scottish National Party (SNP), made the announcement as it prepared to release on Tuesday what it said would be the most detailed blueprint for an independent country yet.
Trailing in the independence debate by about 10 percentage points, the SNP hopes to seize the political initiative with the publication of the prospectus, which it says will shift the dynamic and the momentum of the debate in its favour.
Naming a precise date is part of a plan to try to make the idea of a breakaway more tangible in voters' minds.
"We have previously said that we would aim for Scotland to be independent in March 2016 and in the white paper we go further than that and name the date of the 24th of March," Nicola Sturgeon, Scotland's Deputy First Minister, told BBC TV.
The blueprint for independence would set out the economic, social and democratic case for independence, she said.
"It demonstrates Scotland's financial strengths and details how we will become independent - the negotiations, preparations and agreements."
Alistair Carmichael, Britain's Secretary of State for Scotland and a prominent campaigner against independence, criticised the decision to unveil an independence date, saying the SNP was highlighting something less important than serious policy issues.
"We're not hearing any of these questions answered today," he said. "The one question they're answering is one which actually tactically is maybe not very clever for them to do in negotiation and that is to tell us the end game in it all."
Polls show most Scots oppose independence, but that a large number of voters remain undecided, meaning that next year's independence referendum on September 18 remains wide open.
A poll for Britain's Sunday Times newspaper showed on Sunday that 38 percent of Scots backed independence, with 47 percent opposing it and 15 percent undecided.
The SNP says an independent Scotland would be more prosperous and be able to formulate fairer, more tailor-made policies for its 5 million people, while shaking off what it regards as centuries of patronising influence from London.
But Britain's three main UK-wide political parties argue that Scotland would be worse off economically, and would be unable to defend itself or project power on the global stage as well as it can as part of the UK.
March 24 was the date of the signing of the Acts of Union between Scotland and England in 1707, a day nationalists regard as one of infamy.
But the Scottish government suggested in a news release that was purely coincidental, saying it just "happens to be the anniversary".
(Editing by Andrew Roche)