* PM denies scare-mongering over Sept. 18 vote
* Urges Scots to preserve 'family of nations'
By Belinda Goldsmith and William James
LONDON, March 14 (Reuters) - British Prime Minister DavidCameron urged Scots on Friday to heed warnings from the head ofthe Bank of England and business leaders about the uncertainconsequences of voting for independence in a referendum in sixmonths' time.
Cameron told the Scottish Conservative Party conference inEdinburgh that the government faced a "monumental battle" tokeep Scotland as part of Britain at the Sept. 18 referendum.
Dismissing accusations from Scottish nationalists of tryingto bully Scots into voting against independence, he said thevote was a major life choice, and no decision should be taken without full awareness of the consequences.
Business leaders have raised concerns about Scotland leavingthe United Kingdom after more than three centuries of union withEngland, fearing uncertainties over currency, tax, regulationand membership of the European Union.
All three main UK political parties have ruled out sharingthe pound, which is the Scottish government's preferred currencyoption if voters back independence.
Cameron said the warnings had come from non-partisanfigures, with leaders of oil giants Shell and BP and financial services heavyweights Royal Bank of Scotland (RBS), Standard Life, and Barclays all joiningthe debate in recent weeks.
Bank of England Governor Mark Carney has been at pains notto get embroiled in the political debate over Scotland, but hasset out the difficulties of any currency-sharing arrangement andhas said that RBS may have relocate to London in the event of aScottish split.
"The idea that these are empty warnings and politicalscare-mongering is a myth - and we owe it to the people ofScotland to take that myth apart," Cameron told party activists.
His intervention comes after an opinion poll found supportfor independence was at its highest in six months. A Survationpoll found 39 percent of Scots planned to vote Yes forindependence, compared to 48 percent No and 13 percentundecided.
Scottish leader Alex Salmond argues that Scotland, with itsoffshore oil reserves, could be a prosperous nation, and thatindependence will give it the chance to raise and spend its ownmoney rather than being directed by a London-based government.
He has accused the pro-UK "Better Together" campaign ofscare-mongering about independence, dubbing it "Project Fear".
Cameron said that voting against independence did not meanchoosing to keep the status quo between London and Edinburgh,and that the process of transferring policymaking powers toScotland'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 Britishofficials to warn against complacency as the referendum nears.
Cameron last month stepped up the debate with a speech atthe cycling venue used for the 2012 London Olympics. In whatcommentators dubbed a "love-bombing", he declared to Scots: "Wewant you to stay".
On Friday, he returned to the sporting theme as he lookedforward to Scotland's hosting of the Commonwealth Games in July,and described the union with England, Wales and Northern Irelandas a "family of nations".
"We'll see the strength of that family again at theCommonwealth Games this summer. When the call went out forvolunteers at Glasgow 2014, more than a quarter of those whoresponded were from elsewhere in the UK ," he said.
"Because it's not 'over the border', it's not a foreigncountry: this is our home, and when any corner of these islandsneeds back-up or support, the rest is there."
