* PM denies scare-mongering over Sept. 18 vote
* Urges Scots to preserve 'family of nations'
By Belinda Goldsmith and William James
LONDON, March 14 British Prime Minister David Cameron urged Scots on Friday to heed warnings from the head of the Bank of England and business leaders about the uncertain consequences of voting for independence in a referendum in six months' time.
Cameron told the Scottish Conservative Party conference in Edinburgh that the government faced a "monumental battle" to keep Scotland as part of Britain at the Sept. 18 referendum.
Dismissing accusations from Scottish nationalists of trying to bully Scots into voting against independence, he said the vote was a major life choice, and no decision should be taken without full awareness of the consequences.
Business leaders have raised concerns about Scotland leaving the United Kingdom after more than three centuries of union with England, fearing uncertainties over currency, tax, regulation and membership of the European Union.
All three main UK political parties have ruled out sharing the pound, which is the Scottish government's preferred currency option if voters back independence.
Cameron said the warnings had come from non-partisan figures, with leaders of oil giants Shell and BP and financial services heavyweights Royal Bank of Scotland (RBS) , Standard Life, and Barclays all joining the debate in recent weeks.
Bank of England Governor Mark Carney has been at pains not to get embroiled in the political debate over Scotland, but has set out the difficulties of any currency-sharing arrangement and has said that RBS may have relocate to London in the event of a Scottish split.
"The idea that these are empty warnings and political scare-mongering is a myth - and we owe it to the people of Scotland to take that myth apart," Cameron told party activists.
His intervention comes after an opinion poll found support for independence was at its highest in six months. A Survation poll found 39 percent of Scots planned to vote Yes for independence, compared to 48 percent No and 13 percent undecided.
Scottish leader Alex Salmond argues that Scotland, with its offshore oil reserves, could be a prosperous nation, and that independence will give it the chance to raise and spend its own money rather than being directed by a London-based government.
He has accused the pro-UK "Better Together" campaign of scare-mongering about independence, dubbing it "Project Fear".
Cameron said that voting against independence did not mean choosing to keep the status quo between London and Edinburgh, and that the process of transferring policymaking powers to Scotland's devolved parliament would go on.
"A vote for 'no' is not a vote for 'no change'," he said. "We are committed to making devolution work better still."
Although the separatists are still trailing in support, opinion polls have narrowed this year, prompting British officials to warn against complacency as the referendum nears.
Cameron last month stepped up the debate with a speech at the cycling venue used for the 2012 London Olympics. In what commentators dubbed a "love-bombing", he declared to Scots: "We want you to stay".
On Friday, he returned to the sporting theme as he looked forward to Scotland's hosting of the Commonwealth Games in July, and described the union with England, Wales and Northern Ireland as a "family of nations".
"We'll see the strength of that family again at the Commonwealth Games this summer. When the call went out for volunteers at Glasgow 2014, more than a quarter of those who responded were from elsewhere in the UK ," he said.
"Because it's not 'over the border', it's not a foreign country: this is our home, and when any corner of these islands needs back-up or support, the rest is there."